From what I responded earlier:
"I'm about 5'10" and a 76in long quilt works well, one with a toe box construction, so keeps my feet enclosed. You've said how a longer one works for you better, so you certainly have that as a reference.
With quilts, the system of a couple of small straps that go under your camp mat to hold the quilt in place actually does work well I've found. It allows you to toss and turn , keeping the quilt over you properly."
Id say the comfort thing might be personal, plus like I also mentioned, your camp mat insulation r factor and what you are wearing are all going to play a part in comfort for a given temp.
What really appealed to me with the quilt I got was how light it is, and compressed small.
I hope this fellow gets a bag or quilt that works for him.
Oh, sorry, I meant I am also curious how tall the OP is.