Raising peacocks is not so easy, considering the origin of these birds. As tropical birds, it can be a bit challenging to raise peacocks in temperate regions.
Space is very important for your peacocks. If you cannot give your peacocks enough space for them to roam freely, even in winter, you should not raise them until you have the space.
Make sure that the coop has windows to permit airflow. Also, you can decide to open the coop door but make sure that there is no wind blowing as peacocks don't tolerate drafts very well.
Your goal is to keep your peacocks healthy, even in winter. The best way to tell that your peacocks are healthy is when they are eating and drinking. Do not reduce their feed in winter.
You can trick your peacocks into becoming active at night when you give them light. Only do this if you want them to be active or to eat at night.