Hi! I have some plans for a small coop to hold about 8 chickens. It is made from 1/2" plywood, and no insulation. It does have adequate ventilation, nest boxes, roosts and dropping board. Will this be warm enough in winter? We get in the 20's on average, and a little lower once in awhile. If it won't be warm enough could I use a low wattage light bulb at night?