All are good options above. I know this might sound archaic, but an array of small candles do wonders for heating a small space like a snake room in an emergency situation. The key is to have an insulated room in the first place to keep all the heat in. Tea candles are exceptionally cheap and can be arranged on aluminum foil baking trays, and placed next to the snake enclosures. You would be surprised at the amount of heat that a few dozen small candles can emit. In a pinch this can keep your temps up until power returns.