Taking the Highway 11 route you will enjoy a night or two in Quetico Provincial Park at Dawson Trail Campground - this is the only car campground in the Park. If you are paddlers then an extended canoe trip in the park is pretty much a natural choice for some solitude, adventure and fishing. There are several other Provincial Parks on the way to Kenora - Caliper and Sioux Narrows Parks are both operated by the town of Sioux Narrows. Closer to Kenora is Rushing River Provincial Park - it's very popular during the summer months so reservations are a good idea. The Ontario Parks website will give you more detail on each Provincial Park and give you access to reservations:
www.ontarioparks.ca
You don't say how you are going to make a loop back. One suggestion you might want to think about is to go a little farther than Winnipeg before heading south back into the U.S. and take in International Peace Garden:
www.internationalpeacegarden.com
Peace Garden is located directly on the International Boundary between the U.S. and Canada Border Crossings - managed by both the Province of Manitoba and the State of North Dakota. There is a campground on site. You can easily spend a full day there. If you haven't been there before it is a place you will not regret visiting.
Enjoy your trip.
Jay
2002 Bambi 19' - the "Toaster"
2009 Nissan Pathfinder - the "Buggy"