As I replied to @ted, I became familiar with some Norwegian- and Swedish-American traits when I went to college in Minnesota, and I recognize what you’re talking about. Very friendly and polite but, to “outsiders,” what seems in a superficial way. (The old “Minnesota nice.”) I will say, though, that my nephew’s Norwegian-American wife from Minnesota (surname “Rogness”) danced up a storm at her wedding, as did her bridesmaids – all of them St. Olaf grads.
I get the Alaska back-and-forthing with western Upper Midwest and the Northwest. My Minnesota born-and-raised grandfather went to Alaska (from Montana) for work during the Depression, and one of my husband’s sisters used to go back and forth between Oregon and Alaska until she settled in Alaska, marrying a Minnesota-born man whose family had moved to Alaska when he was a teenager. They’re planning to retire in the next couple of years and move to the Seattle area. (They’ll live near another sister who’s just moved to that area from Colorado – her husband was raised in Florida by Danish parents, and he still has relatives they visit in Denmark. He is the most taciturn and self-contained person I have ever known. I have trouble imagining him dancing! A friend of mine here in NE, born and raised in Ohio, is Danish on her father’s side – he was born in Denmark and raised all over the place because his father was in the diplomatic service. She’s also quiet and very self-contained. FWIW.)