We don't get anywhere near those temps over here.
But just in case we do, I have a pair of these (for fishing).http://www.skee-tex.co.uk/products/skee-tex-boot-14.aspx
Sir Rannulf Fiennes (polar explorer) likes them, and that's good enough for me
At least my feet would stay warm !
But I bet you have other ways of keeping the chill out over there.
I remember seeing a movie clip somewhere, where at those temperatures, a steaming hot cup of coffee thrown into the air (the Liquid not the cup) instantly freezes !
Stay warm mate.