There is a lot of public land up here where hunting is first come first served, where it is allowed. Private land is by permission, a lot of that spreads by word of mouth as to who allows and who doesn't. Most of those I know either hunt on property of a friend or a friend of a friend, that sort of thing or work the public lands. The actual hunt clubs tend to be pretty exclusive which is what you are finding out. But most private owners are friendly and if you can come with a recommendation of someone they know and trust, you are as likely as not to get permission. Further away from the Twin Cities or other major population centers that is more likely of course. Most Minnesota hunters don't lease either. You are doing the right thing to do your leg work early.

The best thing like with fishing is to find someone local to hunt with and if you are in contact with other parts of the state in your job it doesn't hurt to ask those folks about possibilities in their areas.

A local hunt forum would be a better source of information than here. Only a little googling will provide some samples for you to check out.