Double male extension cord isnt as absurd as it sounds. I'd 10gauge the cable, though, and maybe stick an inline fuse.

A den of thieves err nursing home that I unfortunately once worked in had two separate power circuits. Power outages autoflipped to a generator that powered the "blue" circuit... limited kitchen and all the admin offices.

The maintenance guy showed me the double male rig he had to get power into the "gray" circuit. Since each room had its own a/c-heater, Mike (not his name) would have to shut down a lot of stuff, or you would have ppl baking or freezing... but the Admin folks would be comfortable.

For switchovers, I would stick to plain old brute force switches instead of computer controlled.