IMO a generator is a must-have. We have two refrigerator/freezers and a chest freezer, with probably $600 in rodents in the chest freezer right now since all but four of my snakes will happily eat f/t. I won't even get into the venison or butchered hog in there as well...
Also, I'm not breeding (yet) but when I start I'd hate to lose clutches because a power outage shut down my incubator.
I need to look at cooling methods as one (and soon two) of my snakes are BRB's. Last year we had a four day power outage in July after a bad storm. Our daytime high temperatures were around 100*F outside and 95*F inside, which apparently can be lethal for BRB's. I don't have enough KW available from the genny to run even a window A/C unit as well as the fridges. In a pinch I could take those two to someone who lives about 20 minutes away and doesn't have herps, so no worries about QT or keeping my snakes separate from his, and hopefully his and my power won't be off simultaneously. The boas, BP's, and kings should be fine as long as I made cool water from the tap available during the worst heat of the day.

If we all had to leave... um, I'm glad I have a Suburban and a pickup, because my fur-babies and scale-babies come with me!