Warbonnet Blackbird 1.1 double
yeti under quilt 20 degree
EOS MacCat Tarp

20 degree sleeping bag for over quilt

For cold weather I was going to bring my 20 degree sleeping bag to use as a top quilt. come warm weather, could I ditch the sleeping bag and just use the under quilt? it would save a lot of weight. Do I need the sleeping bag at all even in cold weather with the underquilt?