I live in the mountains at 4000 ft. We already have frost at night, which is very early this year. My ducks sleep in an insulated duck house with the window open a little bit. This prevents fogging up of the windows in it. I must say they love the cold. I let them out this morning at a brisk 35 degrees and you saw steam coming out of their nostrils. They promptly ran over to the pool taking a swim. I've noticed that they did not waste much time preening themselves off. They seem to like the morning cold and walk around a lot. Daytime high will be 75. That is the reason why I've got ducks, because chicken will suffer up here in winter. At least we have 300 days of sunshine up here, which makes it feel warmer then it is. Tonight it will be 45, so not that cold. I still have to build some shelter for them for when they are outside. Got the drawing already and will build it in the next couple of days. It will be a portable 3 sided shelter with roof where I can place hay in it. I will also build a protective thing with roof I put in front of the duck house so the wind doesn't blow in. That will freak them out for a day or so.