Keep in mind, the laws of the state you are in apply. Hence, if you have a permit from ND that MN honors, you are able to carry openly here. Yet, if your home state permit is not honored by MN, and ND permits are not, you are not able to carry here legally. It seems to me you will have to wait until you are 21 and then apply for a non-resident permit, or, if you have established you are a resident here, a regular permit.
For more opinions, check out www.twincitiescarry.com/forum