Last night it got down to 38°F and there was frost everywhere! My spider friend survived. I don't think any of her prey has, though. It's supposed to be 37 tonight. Our drafty house generally supports a 10 to 15 temperature differential with the solar heat harvesting I do each day. With the forced air heat turned on, I can boost it to be 20 to 25 warmer inside than outside, but that's about it.
I had the thermostat set to 60 last night, and it ran and ran. My son dared me to turn the heat off tonight. I've turned it down to 55.
Throw another blanket on the bed: Xena's out of town and it'll be just whatever heat I generate!