Well, BJ, your first big problem might be taking the Makinaw bridge from Door County, Wisconsin to the upper peninsula of Michigan (if I understood your message correctly).
The Makinaw Bride connects lower Michigan with Upper Michigan and does not come close to Door County.
That said, I recommend you take a ferry from Gills Rock in Door County to Washington Island. You can find lodging and resturaunts there. Then, bike across the island and take another ferry to Rock Island. The whole island is a state park. It was one of the first places in the midwest inhabited by Europeans and the island is rich with history and things to see. The island was once owned by a wealthy inventor. See his gigantic stone library built out into the bay so that he could pilot his boats right inside the library. There is no lodging on the island but there is camping. Make camp sight reservations in advance.
You will have to take a ferry back to Door County as there are no ferries to any other locations from Rock Island or Washington Island.
To get to the Upper Penensula of Michigan, you simply head south to the city of Green Bay, and then turn north and follow the Bay of Green Bay up to Michigan. It is a nice ride along the enormous bay and the roads are reasonably quiet and bike-able. I suggest you follow the bay rather than riding inland.