Also, there's this concept of thermal mass - once you heat up you walls, floors, furniture, etc, they retain it. If you keep on letting your house cool down and then heating it up again, you basically lose that stored heat and need to pay for it again. It's cheaper to just maintain the same temperature all the time.
And, as a PNW resident I really need to emphasize this: MOLD. It's a thing.
And, as a PNW resident I really need to emphasize this: MOLD. It's a thing.