It’s getting tougher for Minnesotans to avoid the state’s taxes by spending part of the year somewhere else. Snowbirds and high earners are discovering that they must do more than buy a condo in the Sun Belt and register a vehicle there, after a court decision last year reinforced the state’s ability to use any of more than two dozen criteria to determine who is a Minnesota resident. “People refer to it as Hotel Minnesota,” said Matt Shea, a lawyer at Gray Plant Mooty. “You can come any time you like, but you can never leave.” To determine tax residency,...