I have a sewing machine, and I'm not afraid to use it! Perhaps I might put elastic straps on the back side instead of making a whole bag.

I would prefer a down quilt. I see Thermarest makes a quilt specifically for the NeoAir, but that seems like overkill. And too much like a mummy bag, as it still pins you in.

Maybe I should just visit my local sheet and quilt store and ask them?