My snake room is rigged for too low also. My radiator is on dual external thermostats set for the too high possibility. These guys are set to operate in the 84-86 degree range. I have another unit that is your typical blower ceramic type unit that cuts on at 82 for when the radiator cannot keep up. This only happened once this year. On top of that I have the house itself which cuts heat on at 75 and air at 88. It is quite a balancing act and will be even more so when I add the snake room independent ac.
I don't run battery backups since my units all have flash RAM and will keep their settings even if powered down. I do have surge protectors on everything.
I have made no attempt to resolve long term power outages. The temperature where I am at is usually not so bad that I could not get through a week or two with no power. I would end up loosing a few hundred dollars worth of rats in the freezer though.