>>321435There's some video on the Youtubes.
Where two guys camp out in -30, can't remember if it was C or F, but that low it doesn't really matter.
They use underquilts and layer up properly.
Honestly though, if you're intentionally /out/ing in the cold your pack weight goes up signifigantly for warmth(clothes+shelter/sleeping).
Here we are.
www.youtube.com/watch?v=CTuGJgka1qc-40F which is where C and F meet.
The guys a little... different. But the video has lots of good little tidbits, and he does what he says.
