one in the basement to keep the pipes from freezing and another in the "warm room" where we would live and sleep until the power came up.
I would imagine they have special pipe warmers that could run off a battery in a winter outage type situation. Or worst case scenario you have to run a heat lamp (We use those down here to keep wells warm in winter) off a AC/DV inverter off a car battery or something.
Not terribly practical, I'm afraid. Heat tracing and heat lamps suck a lot of juice -- too much to run off a battery or car inverter system for more than a couple of hours.
In that situation, I would rapidly be doing a gravity draindown of the house potable water system, followed by a blowdown with an air compressor, and then RV antifreeze in all the water traps (sink, toilet). That's SOP for winterizing seasonal cabins and RVs up here. I keep a few jugs of RV antifreeze around at all times for exactly this reason.