Why are you leaning toward the heavier birds? Knowing that could help a lot with my suggestions.I’m leaning toward heavier dual-purpose type breeds but I’m open to suggestions.
So your record highs are around 110 F (43 C) and record lows around -30 F (-34 C). These are records, so not what you will see that often but it can still be pretty brutal. I'd consider that when selecting breeds. Some are more cold hardy than others and it is not always the ones you'd expect.I live in North Idaho, so we get all four seasons with hot summers and cold winters. I’m also expanding my run and coop, so space won’t be an issue.
The biggest risk is frostbite of the comb and wattles, bits can turn black and fall off. That's usually more cosmetic than truly dangerous but it would bother many people. Pea combs and rose combs are less susceptible to frostbite than single combed chickens. A lot of people keep single combed chickens around you and do OK, but is is another potential issue.
I'll attach a link to Henderson's Breed Chart. It certainly does not have all of the breeds in it and has none of the crosses and "specialty" chickens offered by a lot of hatcheries but it may be a starting point.
Henderson's Handy Dandy Chicken Chart (sagehenfarmlodi.com)
I don't know what chickens are available to you. I assume you are getting them from a hatchery? If you have a specific hatchery in mind you might go through what is available and see how they compare to others.
Chantecler and Buckeyes were specifically developed for colder climates but are not widely available. Ameraucana aren't that big but have pea combs so are generally cold hardy. Brahma, Dominique, and Wyandotte might suit you. Practically any other breed I'd suggest would be single combed. You've already got some and they could work out well.
