I have 6 chickens in a 6 x 12 uninsulated coop. The walls and roof are made of chicken wire. One side backs to my garage but the other 3 walls are exposed to wind. This will be my first winter with the birds and I'm not sure when to supplement heat and light for them to keep them warm and laying. Advice? I'm in the Pacific Northwest (Kitsap County), zone 6 or 7.