Sounds kind of like mukluks, but there are variations on them, like most every other piece of gear. For camp, I have a pair of SD down booties, but they really aren't good for walking in much more than a few yards at most. Other booties have better soles than mine and are probably much better for footwear. I just use mine in my tent for the most part.

I bet you could use a down bootie inside something like a NEOS overboot.