We went a week once. It was in the low 40’s in the house. We ended up going to bed at 7 pm, and up when the sun rose.
We had a fireplace to keep the house from freezing, so that was OK. It’s amazing how quickly you revert back to Little House on the Prarie.
Yes, however, I often find a fireplace rather comfy even when the power is out. Of course after a day or two you begin to appreciate living in a time when electricity/natural gas is available. I do crave moral “simpler times” depicted in Little House on the Prairie, especially Charles Ingalls’ code, but oh well.