On the cheapest end, pick up a styrofoam lined shipping box and some (24 to 40 hour) heatpacks. If the power goes out, place the snake in a pillowcase and tie the end. Place this in the box on one side. Wrap the heatpack with a loose bit of newspaper and stick it to the other side of the box. Crumble some paper between the heatpack and the snake. If you have a wireless thermometer or one with a wire probe, you could also stick the probe in the box too so you can monitor temps, but this is how snakes are shipped so the snake should be good for many, many hours.

If you have multiple snakes, I would suggest something like a Mr. Heater(tm) "Portable Buddy" Propane Heater. I used one here in Maine (where we get serious winters) and it has saved my snakes (and kept us warm) a few times. I picked mine up locally for $69.00 and it was worth every penny. You can get extra value if you use this when camping, in the ice fishing shed, in the hunting camp, etc. too.

As I mentioned, that worked fine to heat a room or two of the house in a pinch, I did finally upgrade to a Guardian Standby Generator. It was the purchased from the money I received from selling about 14 of my Argentine black and white tegu hatchlings. (around $2000) The feeling of safety I have when I leave home in the winter and know that if power goes out, this thing automatically turns on, is without value.

Rick