Ideas
You have a great boat for this trip, and you will be able to learn about the boat as you travel the Great Lakes.
Some "must see" crusing grounds - each is worth a week or more - on your trip:
The Apostle Islands. If I were you, I would put in in Bayfield and spend a week cruising this beautiful National Shore Line.
The North Channel. This is worth two weeks. If you like anchoring out in the wild, this is one of the best cruising grounds on Earth!
Long Point on the Canadian side of Lake Erie.
If you take the Wellend Canal to Lake Ontario, the Thousand Islands at the entrance to the St. Lawrence is another gorgeous cruising ground.
Lastly, I recommend you consider joining the Great Lakes Cruising Club. They have unbelieveably good documentation (online, hard copy, and CD-ROM) of all of the above cruising grounds, of every port on the lakes, and several cruise logs, including the Great Loop, and a recent one from Superior to Erie.
I would not have a problem laying out a cruising plan for a leisurely trip through the Great Lakes from Superior (Bayfield) to Champlain in three months. You could always skip the Ontario and Thousand Islands destinations by taking the Erie Canal if you want to take more time.
Of course there is the issue that this will put you in the ICW in September - the height of hurricane season. But there are places to lay up all up and down the ICW. Go for it - this is a great concept.