The route through the U.P. will probably be influenced by where and to whom the "baton" will be handed off.....will it be to the Cheeseheads just north of Green Bay or more toward the Minnesotans around Duluth? The former would suggest US-2, following the Lake Huron I mean, Lake Michigan shore---a good but not great 2 lane highway, and pretty truck-intensive at times, but certainly not a horrible route. The latter would indicate following more of the Lake Superior shoreline and could include some pretty nice scenery----new pavement through Pictured Rocks National Park, and the hilly Marquette and Keweenaw area. A route through the northwestern part of the U.P. is more likely to have have hills and twisties, while the southern part is flatter.
I'd agree about T-falls being a bit out of the way, though I'd recommend any biker make future plans to ride all of Curley Lewis highway going west from Brimley, as well as the twisty section of M-123 that goes from Paradise to Newberry, past Tahquamenon State Park.