How to Get the Most Out of Time in Michigan

[CarnationSailor]

My wife and I are planning a trip to the Midwest from the Seattle area next June. The purpose is primarily to visit family in central Illinois and see sites going and coming. However, we also want to spend about 15 days seeing the sites of the upper Midwest (Michigan/Wisconsin). Since this may be the only time we get to the Midwest, we want to spend the time exploring the best areas. (No little ones so only interested in senior adult activities and places.)

We have been told that Michigan's Upper Peninsula (UP) is a "must see", and my wife wants to see Door County, WI.

After a little research, I came up with this:

5 days in Straits State Park (to see Mackinac Island & other sites on the southern part of the UP)

5 days in McLain State Park (to see Keweenaw Peninsula & other sites on Lake Superior)

5 days in Door County, WI

Is this a good plan?

Are there any "must see's" in lower Michigan since we have to drive thru it anyway?

Would we be better off to pick one stop on the UP (instead of two) and spend 10 days there?

Thanks

[WE-C-USA]

Start out, the first 5, by spending at least two nights at Sleeping Bear. Then 3 in the Mackinac area.

[Big_Katuna]

Door County didn't do a lot for us. But I spent lots of time in Ohio Amish country.
A few days there is plenty and use the extra time in the lower peninsula. Go down the west side. Sleeping Bears Dunes, the cliffs, Grand Haven.
Google "Things not to miss in Michigan".
It's a beautiful state.