REI Co-op - Magma 15

A 15 degree bag will keep you warm at 25 degrees. You'll want an additional quilt or a lighter bag for the coldest nights. If you need to backpack it in, down is worth it. I have an REI 15 degree down bag. I bring a 30 degree down bag as a blanket when it gets to the low 20's. I have a -20F down bag, but it takes up too much space if I don't really need it. If you're close to your car, synthetic bags are much cheaper.

Gnarly! Sounds like some top tier "type B" fun. Early on in backpacking, after several uncomfortable, borderline worrisome nights sleep in my 20°f Kelty bag I learned the advertised temperature ratings of sleeping bags are actually the "survival rating,", meaning you won't lose any appendages to the elements. The comfort rating is always significantly warmer than the survival rating and you often have to research equipment in advance to find thst figure. I'm PNW-based, and personally, fall-winter I use a rei magma down 15 bag & neoair xtherm pad. I might not ook like Jeremiah Johnson all bundled up but I sleep like a baby. Risking death chasing the bushcraft aesthetic in a cold, damp environment isn't worth it if you lack the ability or materials to craft an adequate sleep system.

Featherstone tent, REI sleeping bag from their used gear section. Edit: took a WELL used featherstone granite 2p tent on the Great Divide Bikepacking route. 69 consecutive nights of use in all types of weather. Rain, snow, high winds. It was Bombproof. It still had tons of life left at the end. Picked up a used REI magma sleeping bag from their used gear section and used it for 60 consecutive nights of bike touring in South America. I still have it and it still works great.

Did you get the new magma 15? I got each the 30 and the 15 and while I love them, I feel like there’s such a huge gap in temp conditions. The 15 I’ve slept in down to about 22 and it was WAY too warm still. If I slept in the 30 down to 22 I’d undoubtedly be cold. I just think it’s bizarre they came out with two bags that seemingly have a huge gap.

Oh nice! I’m kind of jealous of that 15. I’ve used it before and it’s really awesome. When they made the new ones they started making them unisex, so the lower limit became more of the men’s comfort rating and the actual number became more of the women’s. Your 15 fills the gap in talking about a whole lot better. Granted I did get the wide version and it’s so so comfy so I guess I’ll deal

If you want light weight, small packed size and good temp rating… the magma by REI is the best bang for the buck… because of the size choices. If that is to much… The Trailmade is super inexpensive, and comes in a variety of lengths and widths. It is not as light, nor as compactable. If you were in the store, I would ask a whole bunch of questions… side, back or stomach sleeper? Do you roll? Where do you normally get cold? What is the likelihood of the bag getting wet? Etc… etc… I’d ask because there are so many options and each kind of sleeper works with a different kind of bag. But if you want the lightest and most compact… and best bang for the buck… the magma is the way to go? also do not forget to buy or make a liner. No sleeping back should be used without one!

After years of budget backpacking, I sprung for the magma 15 last fall and couldn’t be happier with it. I find it very comfortable at sub 20°. My only complaint is the size. It’s a bit large but not a dealbreaker

My advice: NEMO women's Disco 15. First off, sleeping bag temps (ISO/EN) are rated for slight discomfort. If you want to be mostly comfortable at 30F, you get a 30F bag; if you want to be warm and toasty, you get a 20F bag. If you think temps may drop into the 20s but may realistically be 30s, you should get a 20F bag; if it hits 20F, you're fine but you'll otherwise be toasty. Women's bags are rated at the Comfort rating which is toasty and nice for a warm sleeper, slightly uncomfortable for a cold sleeper - which is the assumption for women. Also what it sounds like you may be: a "cold sleeper"/someone who likes to be warm at night. Know that you can - and should - try other gender bags for fit as you may find better fits across genders. But keep in mind there is ~10F temp difference between men's fits and women's fits (men's will be colder for cold sleepers, women's will be warmer for warm sleepers) and so don't just trade 30F for 30F. In your case, use the "Comfort Rating" as your slight discomfort temperature and adjust from there. Know also that this may work against you price-wise; they do not price based on fill, they price based on advertised temp. So a women's 30 will be the same warmth as a men's 20, but will be priced as a 30, not as a more expensive 20. So the Magma and the Disco may not be warm enough for what you're looking for. Of the listed bags, they'll fit in order of how you listed them: Disco will be the widest, then Big Agnes, then the Magma. The Magma is a true backpacking mummy and won't be ideal for a side sleeper. The Disco has extra space in the shoulders and hips which are ideal for getting on your side in the bag. So for a cold sleeper who sleeps on their side and is likely to have some 20F but maybe mostly 30F nights - NEMO Disco 15. Should check all of the boxes. The one big difference between the NEMO and the Magma is down fill power, which also impacts compressibility and weight. Magma is an 850 while the Disco is probably around 650-700. If you want a similar fill power bag go with the Riff 15. 850 fill down also warms up quicker because the feathers are smaller. It will also probably be more on par price-wise with the Magma. The Riff has all the same features as the Disco though may have a slightly slimmer shape. If you can, go to your local REI and get in each one to see which are comfortable and which are not. But based on the info you've given, I'd suggest either a Women's NEMO Disco 15 or NEMO Riff 15.

Something to keep in mind is the comfort rating vs “lower limit) rating (are we all confused yet?! 😂). For that bag it’s 30f (comfort) and 20f (lower limit). I personally run cold and have a down sleeping bag (REI Magma) that’s comfort rating is 21f and lower limit is 9f and find it perfect WITH layers AND a hearty meal before turning in for the night. Overkill in the summer but for me it’s perfect. Do you know if you sleep cold or warm? What is your budget? Otherwise enjoy Yosemite. It is absolutely beautiful.

That is a dope sleep is pad. I don’t know if I am any help 😂 I’m a big fan of the REI Magma 15 since it’s all I have used and it hasn’t done me dirty BUT it is hella expensive. Which Big Agnes were you looking at? The one that looks like it attaches to your pad?

If you're not into making your own synthetic quilt as suggested above, some sleeping bags come in both a right hand zipper and a left hand zipper and can be joined together at the zippers. Looking now I'm seeing fewer options that do this than before. ☹️ For example the Women's and Men's Mountain Hardwear Bishop Pass bags are left and right zipper respectively, but neither the Kelty Cosmic Down 20 nor the REI Magma bags seem to come in alternating zipper sides. Mountain Hardwear Lamina Eco AF comes in both left and right zips. It's a synthetic bag so it's cheaper but will be a bit heavier and take up more space in your pack than a down bag. But so would a MYOG quilt as described elsewhere.

Remember that you can move your legs around all you like by moving the sleeping bag with them. I sleep in the fetal position in a very narrow bag because I curl the bag into that position with me. (I have REI's magma and it's extremely toasty)

I like the REI Magma