They like that straw! Yesterday that is most of what they did. Sit in the straw. Overnight it hit about -5F and as soon as the door opened, they came out, had a sip of water then laid down on the straw. Mid-day they were walking around a bit but they are getting a reminder of what winter means here. Here is a shot from a few minutes ago (single digits and dropping). Their house is like a giant brooder . You can see they aren't crowded in the center, so they aren't too bad off.
Edit: I also gave them all new bedding today so it would be softer and warmer.
They all look very comfy and cozy.