Really, let them have an opening and let them make the decision. They know more about being a chicken than either of us do. Trapped chickens can turn into a disaster, however, cold weather can make a flock come together.
Your set up is still small, but will be prone to moisture build up if there is not enough ventilation. You do want air movement through the coop, even if it is cold air. You just need shelter from the wind. It will be cold inside the coop, if it is cold and dry, that is just fine.
If it is cold and damp, that will be a problem. You really cannot trap warmth in a barn or coop set up, what you trap is moisture. Make sure the birds are roosting away from the walls and the ceiling. They need space above their heads. The first year, I lowered my roosts in the fall, I was amazed at what a difference it made.
Mrs K
Your set up is still small, but will be prone to moisture build up if there is not enough ventilation. You do want air movement through the coop, even if it is cold air. You just need shelter from the wind. It will be cold inside the coop, if it is cold and dry, that is just fine.
If it is cold and damp, that will be a problem. You really cannot trap warmth in a barn or coop set up, what you trap is moisture. Make sure the birds are roosting away from the walls and the ceiling. They need space above their heads. The first year, I lowered my roosts in the fall, I was amazed at what a difference it made.
Mrs K