It was 13F this morning here, and I have 12 week old babies outside with no extra heat. Granted, there's about 25 of them and they can huddle for warmth, but they're fine. Slowly acclimate them to the colder temps, and they will grow feathers to insulate.
What is the coldest your area of Connecticut gets in the winter?
Exactly--in 25 yrs of caring for chickens in an area where we get a lot of snow and below zero temperatures my biggest problem has been frozen waterers and frozen eggs. The birds have been fine with no heat other than to the waterer. They are kept in an insulated and well vented coop.
Same conditions here but my coop is uninsulated...but very well vented. I haven't yet seen it get "too cold for chickens" here in the mountains. I have noticed that I no longer get any frostbit combs since using the deep litter method in my coop.