Just a head’s up. Room availability is limited at the Horseshoe Resort. They have 1 and 2 bedroom condo units available. Each will sleep 3. (2BR: 2 queens, 1 pull-out; 1BR 1 queen, 2 pull-outs).
There is a KOA campground 4 miles down the road if you really want to go all in on the ADV thing. There are also a few bed and breakfast locations nearby.
Cheaper hotels are available in Barrie 15-20 minutes down the road.