Have a furnace but don't like to feed it so it only gets used rarely, use small space heaters as needed or stoke a fire, but mostly just dress warmly; no AC. Typical temp in the house in the mornings this winter range from low 40s to high 50s depending on weather outside. Summers here house gets a bit warm upstairs so we'll turn a fan or two on, but fortunately the downstairs is sort of sunk into the earth so stays relatively cool even during the days, most nights are relatively cool out which helps a lot.