I had a similar issue with temporary power. I had no POCO connections yet, so I ran an extension cord from the main breaker to a plug. This made my whole installation into something resembling a plug-connected appliance.
BTW, I tore it all out a few hours later when I no longer needed the power.
If a HO desperately needs to power his furnace from a generator, I'd feel more comfortable telling him to disconnect it from the house power and put a cord on it. That way, none of the house wiring will ever be energized.
Personally, I'd much rather that they leave and head for a shelter. If there's no power, there's likely no sewer, water filtration, ambulance, police or fire department services, or any of the other things that we all depend on to live.
