No, it is not legal to camp anywhere without restrictions in Minnesota. Camping is allowed in designated campgrounds, state parks, state forests, and national forests. In some cases, dispersed camping (primitive camping away from developed campgrounds) is allowed in specific areas of state and national forests. For instance, you can find dispersed camping sites in Minnesota's national forests such as the Chippewa National Forest and Superior National Forest. When camping in these areas, it's important to follow Leave No Trace principles and adhere to any posted regulations or restrictions.
For more information on camping options in Minnesota, you can visit Hipcamp.