Don't let the documentation fool you...they CAN overwinter!! I've seen them for years here in the arctic north, and yes, they don't seem to be a problem this far north. I've never had them be a problem in a hive kept outside, even if I do often see them in the hives. I think most of the time my weak hives are early in the year (splits) when it is too cold for the beetles to thrive, and by the time they could take off, the splits are strong enough.
The only hive that was a problem was my observation hive (it stayed warm year round), perhaps they were overwintering in there, but the ground doesn't warm enough for them to pupate until well into summer, so I think that helps keeps them in check.