Hello BD,
Sorry I missed your first call for information, we were out on the boat for 2 weeks! We lived in the UP for a number of years, leaving 3 years ago.
If presented with the time you offer, I would spend it on a circumnavigation of the Keeweenaw Peninsula.
My port calls would be Houghton, Copper Harbor, and Lac La Belle. Isle Royale also interests me, though it's off the grid and probably a separate trip to do it properly.
In Houghton, be sure to have breakfast at Soumi and have the pannukakku (Finnish pancake). There are nearby mine tours (never did it) and a number of small-town shops and restaurants. It is a great town. Try The Library for dinner, and stop for some beer at Keeweenaw Brewing Company.
From Copper Harbor, find a way to be driven up to Brockway Mountain Drive on a good weather day. There are a number of walking trails around the marina, be sure to take advantage of them. There is also kayaking here.
If you have good weather, get out to Manitou Island. There is a dock you can tie to on the north side of the eastern peninsula of the island, then hike a rugged trail east to the lighthouse property. It's a small adventure.
You will find more to do...just dig around on your stops.
Be careful - though you know this - in this area, help is a long way coming and the water is deadly cold.
It WILL be an epic trip, please post a report when done!
Best Wishes
Jeff