Hey @TomV , some great points.
Same situation between me and my significant other, I'm hot she's cold.
Anyway, something interesting has happened a few times to me in the last 4 months.
When I first get into my tent after nightfall or whenever, I'm ok and am able to heat up my quilt.
But...I've been deliberately camping places I can see the horizon to take night photos, and after about 45min to 1hrs, I've gotten cold again, and when I get back in the tent and under the quilt, I have the darnedest time warming up again, like it's time to pull out the hand-warmers or heat up some water for the bottle.
So I find layers don't necessarily work if I'm not generating any heat. I know, my problem.
But who wants to do jumping jacks or pushups at 1am? (lol)
oops, should mention temps were in the 35-45f range, and I'm just sitting in my camp chair taking photos with the camera on the tripod next to me.