FlyerGold there is a registered aerodrome at Windermere on the east side of Lake Rosseau, it is 1,600 feet long and grass, need a shoehorn to get in here but it can be done. The northern departure path is guarded by high terrain and power lines! So you generally depart to the South regardless of winds.

YQA is I think 5 or 6 thousand,and paved. AC has a published IFR approach for it. There is the private airstrip at Deerhurst, and a strip at Utterson midway from Rosseau to Huntsville.

But the best way, is to call Cameron Air. They will fly you from YTZ to Muskoka for $350 in a Cessna Caravan on floats and deliver you to your dock.