Grant, I believe you will find that for most purposes, a quilt and a bag are equivalent. A lot of warmth is lost in cold weather due to extra space, as was said. A sealed bag is often a bit warmer vs a quilt. I agree with Eric. For cold temps you have to go out of your way to bring additional gear for using a quilt for warmth. So, the weight is roughly the same at 20-30F.
The EE Convert is half way between a bag and a quilt and wider, generally. It will likely not perform really well at either task, well…it’s a very tight bag, or too big quilt. A long/wide Revelation is less dollars, lighter and will perform as well.
Like others, I prefer to bring a light (13oz) down jacket. With my 40f bag this takes me down to 30F (I have been down to 20F) very comfortably. It allows me to open it up as a quilt for >40F nights. And in very cold weather (in the 20’s) I can zip it up when using the jacket. I can use the jacket in the evening, morning and night. On warm nights (>60F,) I often just use the jacket to sleep in.
As far as a sleep *system* goes, this integrates the most components in my pack, so, I carry the least weight:
- Jacket – extra insulation
- Long Johns – sleep cloths to help with dirt/bodily oils on the quilt, insulation, emergency cold gear
- Sleep Pad – doubles as pack frame, protects me from the ground, can sit on it
- Shelter – Maintains dry gear while sleeping, hangs wet cloths to dry a bit, blocks IR losses, reduces heat loss
- Pack – Empty at night, it goes under the pad in lieu of a ground cloth
- Rain Jacket – water protection, heat, used as a ground cloth under my pad
- Hiking Staff – Holds up my shelter, hiking
- Stove/fuel – cooking, doubles as extra heat under the shelter
- Pot – Cooking, holds odds and ends, stores shelter for hiking
- Hat – rain/sun, warmth, holds odds and ends if not worn
- Socks – long knee length, wool socks, dry warmth for feet and lower legs
Because everything is integrated, it works well down to 25F or so even though I only use a 40F bag. This is part of going camping. For three season camping/hiking, it works well as UL gear. Getting back to sleeping, there is often a misconception of bags and quilts keeping you warm enough. Either will work depending on your circumstances. A 20F bag is likely overkill and can be extended down to 5-10f. This is quite cold. Most of the gear you carry can be used in some way to help extend a 30F bag/quilt down to 15/20F. IFF 20F is your absolute lowest temp, you really do not need a 20F covering.
Lacking a down covering, I am assuming you are looking at Light/UL camping. You can extend this with “other uses” of gear you already carry. I think a 20F covering will be too warm mostly. I would go lighter at a 30F quilt/bag and look at integrating other components into your overall “warmth” system. Integrate as much as possible, it will save weight over a non-integrated system. Quilt vs Bag is meaningless without considering your overall hiking conditions. On a windy ridge? Near a lake? In a sheltered grove? Even selection of a good campsite will effect overall warmth.
