Remember that if you lose power(AC no work) and you have racks, the upper rack might well heat up more than the lower ones, lower spots are cooler spots.
Overheating is dangerous, and water for all your pets adds up to a LOT of water, so store a LOT!
If you intend to fill your bathtub for water, CHECK to see that it seals!! My tub doesn't seal perfectly, and over several hours, it will leak out until there's none. Not knowing ahead of time could make you have no pet water.
Fill your freezers!! Bottles of water if you have nothing else. The ice thus made will keep everything frozen longer.
If you are preparing in case you have to evacuate, remember the ID cards for each snake, and you can put each card into a ziploc bag and put it directly in with the snake(or a quick ID card made just for travel). Even if Snakey poos in his bag(container) the card will be legiable, CRUCIAL if you have multiple snakes, especially hets.
I hope this helps! All I can think of right now.