REI Co-op - Magma 30 Down Trail Quilt

I use a REI magma 30 degree quilt for pretty much all my trips. It’s very light, very warm, and love the flexibility of a quilt. I bought a cheap liner for the really cold nights but so far it’s totally worth the price (and on sale currently)

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.

I like the REI Magma Trail Quilt as a first quilt. It is rated at 30 degrees and is a decent weight. The REI returns policy makes it a no-risk first quilt.

I just got the magma 30 and would recommend. Compact, lightweight, and very cozy.

Second the Magma 30 quilt. Incredibly small, light and ive never gotten cold with it (until I took it out into freezing temps, which is on me).

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!

I bought the REI Magma 30 quilt in a large, where I would usually buy a medium. It has a sewn footbox. As a side sleeper, with the extra length and width, it works excellent for those warmer nights as it's long enough I don't have to put my feet in the box. Also, I lay the top out flat when I get warm and cinch up the upper when it's cold. I'm sure this is no real revelation for many, but OP may appreciate the versatility. For me, I've slept in it down to 30 with light weight base layers, and have found I can stay comfortable up to high 60s. Humidity does impact that upper end comfort.

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.

Switching to a down quilt (REI Magma30) with a pad was game-changing. I realized somewhere along the way that I always ended up unzipping my bags and just using them as a blanket… so why not just embrace it?

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.