Chickens do not need heated coops, extra light in the coop, and warm winter clothing.
As long as your coop is well built, has ventilation at the top, and is draft-free your chickens will be happy this winter.
Adding lights to the coop should be done only for your convenience. If you need to visit the coop after dark to tend to upkeep, check on the flock, or do any number of chicken care duties, lights make the task so much easier.
The down on your chicken keeps them warm by trapping the body heat near the body. I know people mean well but don’t put clothing on your chicken to keep them warm.
Making sure that your flock has a source of fresh water throughout the day is hard when temperatures drop well below freezing.
And don’t forget a healthy dose of mealworms or grubs to add some protein. Extra protein in the afternoon is great for getting their body temperature up a little before the cold night.