Yeah, I agree with PP, you would have to look at the big picture:
Financial aid
Living costs (Toronto is especially insane)
Travel costs for living far from home
Another thing to consider, the mutherfucking weather. Toronto isn't so bad, but Montreal is absolutely insane in winter and the city isn't great about managing the snow and ice. Someone who didn't grow up in this weather could easily get depressed being stuck in it.
Lastly, the prestige of schools matters most, as far as I understand, in terms of networking opportunities. It's only so useful to have access to top academics in their field in Canada if your kid is planning on staying inside that academic ecosystem. Meaning, unless your kid wants to stay here, what real benefit would they get from studying up here?
Otherwise, at the undergrad level, what does prestige even really matter in terms of career outcomes?
I say this as a Canadian who went to a non-prestigious undergrad school and then to McGill for my doctorate and found the level of education to be identical, but the learning experience at McGill to be generally inferior.
Universities in Canada generally have equivalency, so at the undergrad levels, you can pretty much count on equivalent level of education. It's really only specialized programs or in academic research where schools make much of a difference. Certain schools have programs that others don't, and certain graduate departments have more funding than at other schools, etc, etc, but those differences are really case by case.
If you are serious about sending your kid to Canada, then literally all universities would be great options. The "prestige" of McGill, U of Toronto, Queens, or UBC are all well known here to mean nothing other than name recognition.