I have 4 Buff Orpington's who will be 6 weeks on Tuesday. I still have them indoors. We are having pretty chilly weather in Michigan where I live. The nights are going to be in the 30's this week. Is it okay to sleep them in their coop? They are pretty feathered out. It's our first experience with backyard chickens and I don't want hurt them by putting them out too soon, but their brooder is just not big enough. They have a 16 sq. foot coop, and a 48 sq ft. run waiting for them. Thanks!