Sastrugi (18°F and 28°F variants)

The Nunatak Sastrugi in 22F. If you redistribute the down you end up with a warmer 22F side and then on warmer days flip the bag over to the other side…. The other side turns into a cooler rated 32F side when cinched at the neck line. Keep the neck line open and in my testing you’re good to go-40F. You have ONE bag with a ~20F operating range that is draft free. No silly ass straps, no strap hardware to break, no added weight. Don’t get it with overstuff to make the redistribution above easier. Nunatak has 4 different temp ratings for a reason and Gryphon Gear will make one if you reach out. I have both. Gryphon even makes bags with a 60:40 split. If you’re sticking to Iceland, Greenland, and mountains above 5,000ft, there’s nothing better. Just don’t take it to tropical areas.

I did sleeping bags, then quilts (Nunatak & Katabatic,) and now it’s a Simple Bag like a Nunatak Sastrugi or a Gryphon Gear Full length Elephant Foot. They’re very good. These bags get rid of all of the unneeded weight and hassle of straps, strap hardware, zippers, draft tubes for those zippers and hoods; but eliminate the drafts that quilts have. No one I’ve ever met is going back and Nunatak has 5 temperature versions of the Sastrugi for a reason. Best part is… in one bag you can get a warmer temp rating on top and a cooler one on bottom. It’s two quilts in one. Gryphon Gear will even make one with a 60:40 split, so you don’t even have to move the down. So in one bag you can have 20F side and a 30F side. And if you keep the top open it will be good to 40F. One bag, with a 20F operating range… Nothings perfect though, if you’re in humid areas, just use a traditional quilts. But if you need draftless warmth, but still gets rid of needless items, there’s nothing better.

There is…. It’s called a Nunatak regular Sastrugi or a full length elephant bag from Gryphon gear.

If you’re in non humid areas I would just go to a regular sastrugi. No drafts and bag has two temperature sides once you move the down a bit.

I don’t really know of too many places messing around with FB other than Timmermade- someone mentioned the pad sleeves on BA bags and maybe the zenbivy setup but for UL Dans the only way I know of to get that. I buy used gear and Spent last 3 years with 3 different quilts - year 1: a Zpacks 10 zip around- fantastically warm and light- with it zipped I was over warm in the teens. I loved the ability to fully unzip buttt the superthin d fabric had me leery Year 2: Timmermade FB wren zipper added 20- whoa… Dan does amazing work and this thing was amazing. It weighed in at 22oz, the zipper was easy to use, easy to get in and out of, great in a hammock or on the ground… but I still felt a wee bit constricted in my torso while rotisserie sleeping. This Year -# 3: Nunatak Strugi-q 22- THIS quilt right here🤯…My 3rd Nunatak quilt and Jan and the team have assembled a pinnacle piece IMO. The diff cut, ETC, draft collar, baffles, fabric inner and outer, the stuff and the snaps… I tried it in the backyard without pad straps in the low 30s and didn’t fully adjust the etc and was surprisingly warm for how i flip flop through the night. Next 3 nights I adjusted, added the straps and as the temps crept into the mid 20s I slept through the night warm and woke up warm. FB is great and I enjoyed my time in the Wren- I love dans work and that you can literally build for your body/sleep style and what your needs are… and if you win a spot you can message him along the way of the build and he will help you out.

Fellow rotisserie sleeper here. Mostly camp in my hammock but also go to the ground when I have to, e.g. routes above treeline. I’ve done quilts and mummy bags on the ground, and I don’t like either in their traditional forms. A third viable alternative is what basically amounts to a hoodless “bag” of some sort: a false bottom bag (Timmermade Serpentes/Wren), a zipperless bag (Nunatak Sastrugi), or a fully zippered quilt (Feathered Friends UL Wide Flicker). You have the option to select from a variety of sizes to suit your needs especially with Nunatak and Timmermade, but be aware of the lead times and specific ordering windows that will require some patience and diligence on your part. I find I sleep less interrupted in these types of bags on the ground, while traditional top quilts do just fine in a hammock system with an underquilt.

Nunatak Strugi-Q spent the money and the quality and temp rating was a true comfort rating.

I'm a real tosser and turner and generally side sleep and I really like my quilt for that (not getting tangled). I definitely find a quilt to be not as warm as an equivalent bag though. I now have a -2C rated quilt which I use down to 0C and a -8C sleeping bag I use for anything below zero. I've tried a warmer quilt, but just couldn't stay comfortable below zero. I use an Exped R5 Wide Mummy Pad with 3mm 2/3 length foam pad under FYI. I think the biggest thing that did help the quilt in the cold was wearing a down vest with a hood. Maybe a hooded jacket or a down balaclava would help? And obviously get a handle on getting a decent seal using the pad straps. Have fun

Nunatak out of Moab is the top of the line for quilts. Highly recommended, can be specialized to your body shape. I'm quite tall and thin and they added on a couple extra inches so I'm super snug in my quilt. Just remember to tighten it up and the opening goes under you, but above the sleeping pad. Edit: I see you already have the Nunatak. Great choice!

People comparing their EE quilt temp failings with a Nunatak quilt is pretty comical. Not all quilts are built equal.