What are the temps now, and what will they be dropping to? Most likely, it should be fine. Power shouldn't be out for very long and the snake can withstand a few hours of cooler-than-optimum temps. And if its anything there like it is here, it's pretty warm to begin with.

If you are afraid of temps dropping too low, you can wrap a blanket or something around the tank...or have it ready to wrap in the event the power goes off...to help hold in the heat that is there for as long as possible.

Good luck.