Throw another log on the fire. I like to keep it simple. We grow our own fuel, dead trees, and built a high thermal mass wood stove. Uses less than a cord of wood a year for all our heating. Feed it in the morning and it's golden. Our house is high thermal mass and well insulated with some passive solar gain so even without heat it never freezes even in our cold northern climate. Build appropriately. Design simple systems. Dumb works.