I had an experience where I was working construction in about 5 deg. F. weather. it really, really sucked. Anyway, after the first day, we were all frozen and I went and picked up a pair of good boots with a lot of thinsulate and a thick lug sole. I've never been cold again!
If it is cold you are worried about, get a good pair of boots. The socks will keep your feet comfortable (pull sweat/moisture away), but if its going to be cold, get some boots.