I agree with the suggestion / recommendation of having some kind of insulation under you. I'm one of the ones mentioned that stays warm down to really cold temps, but even I need at least a piece of fleece under me, I have one set up to hang as an underquilt for "High summer" use & it can do double duty as extra insulation in the deep cold. Being bulkier than my down No Sniv, I really don't carry it now, but it does get used in the summer in my house.
For summer hiking trips, the No Sniv goes anyway, & I just hang it with a easily adjustable gap tween me & the quilt. That way if I do get cool I can snug it up, cause a lot of times I have hiked in 70 - 80 degree days, with 40 - 50 degree or colder nights. Add rain & wind, & even someone like me can get cold on a long hike.
When you have a backpack on, no matter where you are, you’re home.
PAIN is INEVITABLE. MISERY is OPTIONAL.