I started off with wool blend socks when I started riding. I then tried a pair of Dakine socks($30+ a pair) but found they were too tight on my calves. I now wear Bonds Pillow Feet (about $14 for 2 at KMart) which are specially designed for people with circulation problems and find that they are sufficiently warm, the loose banding around the top of the sock holds well and find that my feet still manage to stay warm, even in the wet snow conditions that we get here in NZ. Not to sure how they would fear at 10DegF though.
I rate them as a very very comfortable alternative to boarding socks...
Never Summer SL153 & Atomic Hatchet 159