First off I am in GA & fairly new to quilts, my current setup is a 3 season KAQ under quilt, with a cheap 20* mummy bag, I have sleep really warm down to 33 degrees with this setup, I have been looking at going to a top quilt mainly to save bulk. In Georgia most of the time I am camping in 40*+ temps. Occasionally I get into the low 30s. So my question is do y'all think I can get by with a 40* top quilt and maybe layer up for the low 30s? If not are y'all seeing a huge difference in bulk between the 40* & 20* top quilts