All I can say is that there are indeed serious beekeepers up here in Alaska, some that rune dozens of hives. A few guys even run hundreds of hives. An there is an entire club dedicated to being treatment free, although that is the Alaska Bee Club, not SABA. Not a majority, but a good percentage of beekeepers in Alaska overwinter.
I find it interesting you say that everyone, everywhere is the USA uses the same queens and the same brood boxes. That has not been my experience.