If you have cold hardy breeds you should have no problems at all. We are very near each other geographically and I had 4 hens in an uninsulated 2x4 coop with attached covered run last year and they were fine with no heat added at all. Chickens are a lot more hardy than we think and they have nice "down" coats to keep them warm. They ate the same food (layer pellets) with additional treats of greens and BOSS. I occasionally would make a warm oatmeal, feed, scratch mush as a treat. I didn't provide any extra lighting and they layed just fine; a few less eggs here and there, but nothing significant. You may want to invest in some type of heated waterer unless you want to change out water frequently. I got a heated dog bowl from
TSC and that works fine for me. I refill it daily and it stays liquid in even 0 degree weather.
This year I built a new coop (6x6) because I got 4 more hens. I put some insulation in it (for me more than for the girls) and I expect they will be fine. Remember, wild birds don't even have a coop to go into to get out of the weather and they do fine.
The most important thing is to make sure they have a draft free, but well ventilated, shelter to go into. If you provide supplemental heat you risk problems when there is a power outage. If they are used to warmer conditions they won't have made the necessary adaptations for the cold. Give them a roost that they can sit on their feet, such as a 2x4 with the wide side up. That will keep their feet warm and they will cuddle together at night and share warmth too. I also use the deep litter method in the coop so they can cuddle into the shavings for warmth if they really want too.
It's not so much the cold as the humidity. In cold, humid conditions you have to watch for frostbite on combs and wattles. A little vaseline or bag balm will help with that though. If your coop is dry and well ventilated, just being cold really shouldn't be a problem. I've heard of people in Alaska that have chickens without extra heat that do just fine.
They'll decide if they want to be in or out, depending on the weather. If you can cover at least part of their run they'll be happy. Some chickens don't like snow too much, others don't care.
Don't worry too much. Enjoy your girls and good luck.