My feet get chilly sometimes too, I wear my summer hiking boots loosely done up and one pair of wool socks. The other day it was -38F and admittidely I was just biking up the road (~1km), but my boots had been in front of the stove and they were SO warm all the way, I think because the rubber soles held the heat in. Anyway I was impressed because usually stuff gets cold REALLY quickly at these temps. I plan to leave my shoes in front of the heat from now on - simple but beautifully effective