I've thought about power backups quite a bit as well. In looking into it, it seems that virtually every backup generator creates a type of power which is not well suited to thermostats.

I think one of the best responses to heat a snake room in case of an emergency is an oil-filled radiator set in the mid 80's, plugged into a generator. Just heat the whole room and forgo the heat tape during the emergency.

For an incubator, you would have to use the on/off method as described in the post above and have a good amount of air circulation to (hopefully) even out the temp.

Jon