I know this isn't much information to work off of, but I have an old slumberjack 20* quilt that I used back in the day. It has to be at least 14 years old. It kept me warm as a teenager through multiple treks, including Philmont, so it's pretty well used.
About three years ago I used it in the low 30's and it seemed to be at the limit of comfort. So I thought it would work great re-purposed as a summer quilt. I have cut off the hood, un-stitched the zipper, and seperated the two layers (inner and outer). Each layer of outer fabric has a layer of insulation sewn in. So I really could make two quilts.
My question is this - what temperature range do you guys think I could take this down to? I realize this is very subjective and open to so many variables. Just hoping to get a rough idea so I don't take it out in the low 40's and freeze.