This is something you might want to try if you are hunting from a stand. When I went to Saskatchewan I bought a pair of boot blankets from Cabela's, they run like 50 bucks. When you get into the stand slide them on over your boots and throw a few hand warmers in each one. If you are in a blind and have room you can pull your boots off and just use the warmers. It sounds crazy but it works great and is a hell of a lot cheaper than buying a quality pair of brand new boots.
That would be a heat wave sometimes up here, but I know Roger is probably laughin at the both of us about now...