Lake Superior Grand Circle Tour

We are planning a Lake Superior Circle Tour in late September-early October. I'm really struggling trying to make reservations at some provincial parks. I can only assume that they turn off the electricity on Sept. 4th. We have a generator but really don't care to use it a lot. If we must, do they allow unlimited hours or times. Does anyone know of private campgrounds in Ontario,
CA or around the Superior Circle Tour? We would like to travel late Sept.-early October to see some of the colors and avoid the crowds. Travelling in a 32 foot 5th wheel. Thanks for any help you can offer.