I stayed at Big Water Campground on Hwy 655 15 minutes north of Timmins. I stayed mid September for a night and it was really quite. I can't say about mid season. There are a lot of seasonal campers but the rigs are nice and the campground is well maintained. I hope this helps.
2004 Ford F550 6l Lariat SuperCrew, Fontaine Bed,
Link Systems Air Ride
2011 Sterling 32RL with Michelin XPS tires