If you just want sq. miles of trees, we've got thousands upon thousands of them, including the famous Algonquin Provincial Park. But my first choice would currently be the Peterborough area, including the Kawarthas lake district. Peterborough is in rolling hills farm country. For me, having lakes, streams, boating, and locks so close to hills and farm land with barns, fences, and grazing cattle adds up to a lot of visual interest to complement the trees.
Whatever destination you choose in Ontario, I suggest using the
Weather Network forecast to help plan your trip. Notice the useful Fall Colour Report there. The big gamble is always whether some hurricane remnant will come ambling through a given area during the week you've chosen to be there.
