Fellow Minnesotan here. Our state park system is the best in the country, hands down. Our first trailer was a 20 ft Rockwood Mini-Lite that we used locally and all the way out to the Oregon Coast. Decent quality and was perfect for a couple. When one of the kids would meet us on a trip they would tent it. Buy the trailer you two need and don't go bigger just for the rare times you are joined by one of the kids. We have a no slide ORV now but stayed sub-25 ft just for the reasons you mentioned.
A WDH/sway control may be a necessity. Don't choose a trailer just to avoid that. Go quality first then the floor plan.