We have had two holidays in Ontario over the past few years, we absolutely love it and would go back again and again. There is so much to explore once you get out of Toronto, and it’s so child friendly. You don’t have to drive too far to get to some really beautiful places!
Our first trip we spent a few nights in Toronto, then drove to a cabin up in the Muskoka lake region (a couple of hours drive), stayed there for a week exploring all the lovely little towns, spending lots of time out on the water, did some walking in Algonquin Provincial Park. Then we had a final few days in Prince Edward County. We stayed in a town called Picton, really lovely little town, lots of little shops and cafes, close to breweries, wineries, distilleries, all of which had food trucks or kitchens, very open to kids coming along. Also close to Sandbanks Provincial Park, which has gorgeous white sand beaches on the shore of Lake Ontario.
For our second trip we got out the city as soon as we arrived and we went up to some little towns on the shore of Lake Huron. We went to the Blue Mountain resort (which in winter is a ski resort, but in summer is like a massive outdoor playground, we had an amazing day there) we went up to Tobermory and Bruce Peninsula, did a boat trip and some walking. All very beautiful. Went on for a few days in Muskoka area, as we knew we loved it there. Then on for a few nights in a cabin with its own lake access and watersport equipment in the Haliburton Highlands. Another stop along the north shore of Lake Ontario for 1000 Islands, then a final few days back in Picton as we loved it so much.
These trips were done first with a nearly 4 year old, then 10 by the time we were able to return for the second trip. Happy to share accommodation recommendations/specific area recommendations if of interest to you. Eastern Canada seems to get bad press in contrast to the west, but we absolutely loved it.
Edited to add: we made it so that we didn’t need to drive longer than 3 hours between stops, and that was only one of the legs. Majority were around 1.5 hours, so felt very manageable for our child, who isn’t accustomed to super long car journeys. Even the 3 hour leg was fine, as we stopped for a quick walk.