We live in the deep south where winter basically consists of 40 degree weather in January and February. We might get 2-3 days a year when overnight temps get below 32. My coop is 16'x16' with the east wall completely open. The roosts, pictured below, are at window level for maximum cooling in the summer. There is one on the north side and one on the south side of the coop. Should I block off the roost level windows for the winter? I don't think this would have much effect on ventilation.