If you try it, let us know how it goes. I would have tried it out already but living in Florida I don't see much snow. The last time it snowed here was 1994 (before I moved here) and, from what I hear, the snow was gone by the afternoon.

If it does work, it would be good to know that all you realy need is, at most, 3 pair of 100% wool socks stuck in your car for winter survival footware.

As for the ice booties, I belive this, I have seen the belly of a poodle (family pet growing up in California) become caked with icy snowballs when we took him to the mountains as a puppy. I think something similar would happen to the socks, where you didn't move a whole lot would freeze/collect snow solid, where you did move you would just have a crack.