i have a pair of Rocky's and they're good until about 15 degrees F. They have held up pretty good too. I abuse the crap out them in the woods cutting trees and brush. I'm sure if I bought them a little bigger they'd be a bit better warmth-wise. I don't have any issues with the wear on them, though, and the grip is so good on them I'd swear they had opposable thumbs. They grab everything.

I wouldn't say they are the warmest though, even though it says "800 gram Thinsulate"