I am having a really hard time with this. I've read where people do insulate, then people don't. I am in upstate New York and some of our winters get really harsh, talking negative 40 degrees at the least. I don't really have a way of running a heat source up to where my coop is located. The top part of the coop near the roof is being kept open, I am going to put hardware cloth over the openings to prevent predators of any other nuisance of an animal getting in. Should I insulate the coop to help keep the chickens warm in the winter months? Should I only insulate a couple of the walls and leave the other two "undone" so it doesn't get too stuffy, but gives them some extra added heat? Any advice would be greatly appreciated. I am looking to move my girls outside in about three weeks so I need to finish the coop and get it all set up before then. Thanks in advance.