@WIparent4 Check out the “Parents of class of 2020 thread” here on college confidential.
Not only is it a relevant group since your S is a rising senior, but there’s also a similar dual citizen parent in the group that has an older sibling at McGill and can perhaps offer some advice. We live upstate/western NY and my D20 visited McGill and may apply for CS. We’re not Canadian, but they offer a CS program through the faculty of arts & sciences there that’s a bargain for int’l students. Both UofT and McGill are top-notch schools.