In Janesville, everything in Wisconsin is "north," except what's south of Hwy 11. I'm also from Janesville, and except for a couple of years in Green Bay in the 1990s, the farthest north I've lived has been Madison. I'd draw my up-north line between roughly Eau Claire and Green Bay. Not quite 29, not quite 10, but north of the population centers. Some of my Janesville relatives used to have a cabin on the Mecan River near Wautoma. They called that "up north" but I didn't. Another Janesville uncle had a cabin in Manitowish Waters, and eventually retired there. That's DEFINITELY up north.