Ex-homeless dude here - the best advice I can give is to dress in layers. That is your primary shelter. A house is just gravy. You can survive temperatures well below zero if you wear appropriate clothes. They don't need to be clean and they don't need to be pretty. Just bundle up, hunker down out of the wind, and you'll get through it. If you start feeling sorry for yourself, remember that for a lot of folks out there this is just business as usual.