You should check out the winter cycling forum!

Layers, layers, layers. Three or four :-) For my so-called winter riding, the outer layer is a light cycling windbreaker. It's a great insulator! Keeps the cold out and the sweat in :-) Once you warm up, it can be removed. Mine is thin enough that I can twist/twirl it and tie it around my waist.

As I have been commuting daily for 22 miles all this fall, I find that my toes are excellent "wind socks". At any temps under 60F, a head wind can chill my toes! My toes are perfectly happy with a tailwind. I now have winter cycling shoes, one size too large and should be able to keep my feet from complaining.