Michigan has a great network of state/city/municipal harbors every 20-30 miles along the Lake Huron and Michigan shore.
You said 40ft sailboat, but what is the draft? Some of the harbors aren't dredged very deep, and this rarely visited by sailboats.
Port Huron, Lexington, Port Sanilac, Port Austin, Harrisburg, Presque Isle, Rogers City, Mackinac City / Straits State Harbor / Mackinac Island are all Great sailboat stops on Lake Huron.
You have to give some serious thought to your route planning... will you be taking long days and pushing to make the trip quick, or taking a 2-week cruise and sight-seeing your way? Regardless, you have to have contingency plans
We went the opposite direction, Sturgeon Bay to Detroit, and because of family schedule (and those pesky lock-down days of 2020), we went for the long days and pushing long distances.
Our route was Sturgeon Bay to Beaver Island to Rogers City to Port Austin to Lexington to Detroit. So 4-nights, 5-days... ~370NM... longest day was a tick over 100NM and 16hrs, and averaged 80NM & 12hrs each day. That's not for everyone... and can't say I'd recommend it to anyone, but it worked. We were always ready to modify based on weather or issues, but we didn't have any problems.
You can get Michigan harbor info/reservations at
MI DNR. I'm sure others can comment on the Lake Michigan harbors better than me. I like Beaver Island, but you don't need to cross the lake that far north.
The planning is fun, the exploring new little towns and harbors is even better, and the experience will be a fantastic way to start your adventures with your new boat!