HunkerDown 20

The REI brand ones are nice (and true to the temps they say they are good for). I have an REI three season single, and have used it to just below freezing with no problems.

When not backpacking I use a rectangular bag like the Rei hunker down. For really cold (<20) I just use two, one inside the other, along with layers and a warm hat. The rectangular shape is fine for some movement and side sleeping and it’s the same dimensions as my sleeping mat and cot. I wouldn’t want to go much bigger or the space inside is too large to effectively warm with body heat.

Eh, depends on your use case. I'm in Alaska and I use a 20 degree rated REI bag. But I'm also not camping in colder seasons. If I were going out anytime other than between May-October, I'd have a -10 rated down bag.

I absolutely love my REI sleeping bag. It’s very cozy and warm. It’s held up for years and is still going strong.

I have an REI down bag that has been great for the past 10+ years.