Wait I forgot ,you like to fish? then you may have heard of Michels Bay- bass heaven-.Other side across from MB is Rondeau PP should be able to get in on short notice, the closer to Toronto you get the tougher (almost impossible)it is to get into the Provincial parks.
Toronto is Canadas New York city so think about camping near NYC,sound like fun?North of toronto things dont thin out for a 100 miles ,get reservations asap.
Once you turn the corner at Sudbury the pressure is relived a bit.I recommend from the Sault dont cross back into michigan yet ,continue across lake Superior and cross at Duluth and do the circle tour of the big one.
Really the only thing to must see in southern ontario is niagara falls .
