One more thing to add.
You might want to try a pair of vapor barrier socks.
I have a better idea, get a pair of Vapor Barrier BOOTS like the GI bunny boots (white) or mickey mouse boots (black). SMC used to make crampons for them and they were the standard boot for the Muldrow Glacier route up McKinley. They kept my feet warm for two winters in and around Fairbanks/Delta Junction, down to minus 54.
