Sudbury is where I trained on floats - Sudbury Aviation, now renamed True North Airways were great, they operate off a huge lake but have all sorts of more “interesting” lakes available.
I had a great time and recommended them to anyone who would listen, however the instructor I trained with left and the owner at that time has died, so things may have changed. They operate 2 x C172 on straight floats for training and C185 2 x DHC2 and a DHC3 on their charter fleet, there is a sensibly priced hotel in town which I have walked to the lake from.