I was wondering if it is safe to not lock chickens up in their coop at night if they have a fence? I'd say they have about an acre to roam in that fence, and I'm hoping to build a fence around the whole property that I could let them out during the day , and then put them in the smaller one at night. And also how can I let them out during the winter? I live in MN so It gets all the way down to minus 75 on the really horrible days, that's with wind chill though. So thanks in advance!