Or go solar with a battery, or just have a massive battery hooked into your distribution panel and leave the 19th century heating hacks in the 19th century. Optimize what you need for today, not whatever was state of the art 200 years ago. An electric space heater running continuously is enough in an emergency.

If it's really cold outside, an electric heater isn't going to do much if your house doesn't have good insulation. It'll be cranking away on high 24/7 and the room will still be cold. Building direction, window choice, room design, etc all contribute to the overall thermal efficiency so that the space heater can be effective.

> An electric space heater running continuously is enough in an emergency.

Yeah, massive battery and massive solar install might let it run continuously… even in a small well insulated house that’s gonna be using a lot of power to heat a room or two.

I don't think you understand how much power electric heaters use and how poorly solar converts to electric heat BTUs. A heat pump would be better.