Spoonbill UL 2 Person Sleeping Bag

I sleep rather cold. I could never make a quilt work for me I says wanted the sleeping bag hood and no air drafts. So it’s the Xtherm and western mountaineering versalite 10 degree F or ultra lite 20 degree F bag for me in almost any US mountain west situation when I’m alone. I think western mountaineering is king sleeping bag maker in the USA. You Could look for used or sales on the Bags because I think they’re more than $500. When I hike with my wife I do a 10 degree accomplice double quilt from Enlightened equipment. I do find the other body heat helps. We tried a ff spoonbill which has a hood but it didn’t work as well as the quilt with two. So I have to be mindful of drafts. As others said eat something before bed, pee, and eat something else at night if you wake up cold and pee if you need to. Also there’s some argument to be had for naked sleeping in a sleeping bag that’s warm enough vs wearing puffies to sleep in. I personally always wear down pants and jacket to sleep if it’s cold. Also campsite selection can contribute to cold.

We have a Big Agnes something or other 15 degree down bag we bought for around $300...10 years ago. It's great, although more like a 30 degree bag. Size / weight is about equal to two sleeping bags. We also tried out Feathered Friends' Spoonbill which is well out of your price range but might be interesting to look at to see how an actually warm two person bag looks.

 So the problem with any normal two-person sleeping bag is that there's an air gap between you if you don't sleep snuggled up.  The Big Agnes we have has a small flap that covers that up. We have also stuffed clothes in between us when it was colder. That works for 15 to 20°, but not colder. The reason I said the spoonbill was interesting is that it has individual draft hoods for each person so you share warmth but actually can't cuddle. 

I worked at a man camp for one winter. Used a down 20 degree sleeping bag most of the time, but also had a second bag to double up when it dipped down lower. A sleeping bag is a lot warmer than a quilt. I slept through a few -20F nights without much issue. I had a lightweight Feathered Friends bag, but I recommend a heavier weight material for hard use if weight isn't an issue. I remember fixing a hole or two with some duct tape. I still use that same bag.

Feathered friends will customize bag sizes. At 950 fill power down they are as lightweight as you can reasonably get.

The ratings are not always reliable so you are right to be uncomfortable with them. One good baseline is ounces of down at the same fill power. Comparing bags that way gives you a better comparison point. Western Mountaineering and Feathered Friends are generally reliable in their ratings. That should give you an excellent place to start.

Feathered Friends will customize bags. They did it for me.

Western Mountaineering, Feathered Friends or Marmot for bags. Enlightened Equipment, Hammock Gear or Katabatic for backpacking quilts. Not cheap but quality and comfortable.

I've been a quilt user for years, but if I were looking for sleeping bags, I would go with either Western Mountaineering or Feathered Friends. You absolutely get what you pay for with either brand. Awesome quality.