Dan is right about 69, it's probably not safe, there is a lot of fast trucking traffic and tiny shoulders. Not much there to see that route anyways... Tobermory has a nice park to visit/camp and the main highway south(hwy 6) from there i'm told has paved 1m shoulders for a distance. If you want to skirt around the southern points of georgian bay it would be nice, avoid Wasaga beach/26 on the weekends.
I also ridden through the area of 35/118... this is cottager country so on friday afternoon and sunday evening traffic could be intense, try to avoid it. You'll be skirting around the cottage I visited near west guilford in the summer. I went up north through bobcaygeon through.