That was a really great question and one that I have thought about as I live in the country and we do have occasional power interruptions due to falling trees, wind, snow, ice or other disruptions.
I was not aware they could handle temperatures down around freezing but I would never allow that to happen if I can help it.
We do have a wood stove, a home made papa bear stove, we have 2 fireplaces and we have a building full of wood so that is our backup heat if the power goes off. What we do lack is a generator to run the well pump, fridge, freezer and hot water heater, those are the things you really miss when the power is off.