@apainter
@jenniferhunter gave some good recommendations.
I would also check this discussion:
https://connect.mayoclinic.org/discussion/travel-and-connections-while-at-mayo/
I live in Rochester, and due to Mayo upgrading and building a new building, the construction downtown is bad—many detours and some travel congestion.

I strongly recommend staying at a hotel connected to Mayo by subway (walk) system. Though they may be more expensive. 2nd alternative is a hotel with a shuttle that will take you right to the door of Mayo / Gonda building.

Check Mayo's construction site for more information:
https://www.mayoclinic.org/rochester-construction