Sierra Designs - Frontcountry Bed 20 Duo

The Sierra Designs bag the person above recommended answers all of this. You should probably look at it.

It says right there. The Front and Backcountry models.

Sierra Designs has or had one recently. I tried it out but didn't like it much and ended up going with a Zenbivy which is exactly what I hoped it would be.

I also got an EE quilt and have thoughts on rating - I opted for a 0° bag but this was motivated by spending some uncomfortable nights right around 35° in my Sierra Designs down bag that was rated at that. With a quilt the zero seems overkill but the design has meant I've been comfortable in much warmer temps despite being a warm sleeper generally. I can open it up, hang a leg or arm out, or be just partially covered. They key with the quilt style is having a pad that is matched for the temps you're in. On my last trip i still took my Sierra Designs bag as it packs slightly smaller than my ee quilt but this setup works for me to cover a wide range of temps. Admittedly I missed the mobility of the quilt compared to the mummy but I've spent most of the last 30 years in mummy bags so it's not unfamiliar.

I have a Sierra Designs sleeping bag that has an actual foot flap that allows you to have your feet out of the bag while your body is still in the bag. It’s great. Highly recommend.