Canada Road Trip Vancouver to Quebec City & Niagara & Back

Dear Friends,
This summer we are planning to take a road trip from west to east and back keeping a total travel time of 3 weeks. Our on the way stop points are Kelowna, Rookies, Banff, Jasper, Icefields parkway, Regina, Midland Ontario (Muskoka resort region), Ottawa, Montreal, Quebec City, 1000 Islands, Toronto & Niagara Falls and Back.
Appreciate if could advise any other interesting points? Natural scenic beauty or adventure related
We would like to drive within Canada and will avoid crossing borders.
Your experiences in these routes are welcome,
To be honest this will be my first such a long trip,
Any preparedness advice is also welcome,
Thanks,

Just wondering...Have you completed your trip? If so, how did it go? What were your highlights?

bruce penninsula national park in ontario.. somewhat close to midland depending on the route you take