My wife, 3 kids and I (ages 9-14) just did a week in Ontario at Grundy Lake Provincial Park/ French River Provincial Park/ Niagara Falls
Canoe camping: Hartley Bay Marina, Alban Ontario to Georgian Bay and back. We did the "Figure 8 loop" in 4 days/3 nights with no trouble though you could easily take an extra day. Only 2 fairly easy portages. This was my favorite vacation ever, kids loved it, wife liked/tolerated
(This is not the kind of camping where you have any plumbing - though "Thunder Boxes" could usually be found)
You do not need to be a "pro" camper or canoeist, but you need to be able to read a map and use a compass with some proficiency. (or you might have one of them new-fangled GPS thingys)
(We drove with 2 canoes on top of the minivan, but I know Hartley Bay Marina can completely outfit you - there are probably several other outfitters as well.)
We camped at Grundy Lake Day 1, French River Days 2-5, then stayed at a hotel near Toronto. Checked out Niagara Falls, then drove home.
We all had passports, I thought Canada required passports now?? Might want to double check on that first.