Hi Laurie,
I had really frozen toes today too. See my post in "December 29th Friday rides" thread.
It's getting more consistantly cold here now in NY state.
I can't speak for how others handle the cold, but here's what I do:
For a 4 hour ride in 31F today, I had to wear my heavy Thinsulate hiking boots. I don't use clipless, just PowerGrip straps on regular pedals- that way I can wear heavy warm boots with room inside for heavy socks. With my boots today I wore Smartwool merino knee socks and a pair of very thick warm hiking socks. Still wasn't quite enough, so next time two heavy pairs and will skip the thin smartwool socks. (I wear two pairs of winter tights as well, and two pair of gloves.) I really don't know how people can keep their feet warm in clipless shoes, even with neoprene booties, but the booties are what people recommend for clipless coldness. There doesn't seem to be any room for heavy socks. I admire them if they can keep going, but I think it must be hard to keep warm enough with clipless shoes. I am assuming you are wearing clipless.