they should do fine, we have quite the varied climate here in NY too and they all seem to do fine. On the days where it gets below 0 degrees I don't open the doors for them to go out, but they wont go out in that cold anyway. Create as much wind blockage as you can in the winter and they will decide if they want to venture into the cold. I would worry more about the 115 degree days than the cold ones. We have had a variety of chickens and they all do well in the winter as long as the coop conditions are dry. I have had 1 rooster with a real big comb with real tall points get frostbite but that can be prevented. My coop that has a little insulation (not much) usually stays 10 degrees warmer than outside in the winter and I do not heat the coop. Last winter was pretty mild for us, but the year before was brutally cold. Get a water heater for the winter and in the summer make sure they have shade and a fan.
