Do you have any budget constraints at all?
Unless you are offered a lot of financial aid, a bachelor’s degree from Toronto plus a master’s degree from Stanford might cost quite a bit less than just a bachelor’s degree from Stanford (and I do know two people who have done just that). Of course you would need to do very well at Toronto (or Waterloo, or McMaster’s, or McGill, or any one of a long list of other very good universities) to get into a graduate program at Stanford.
You have a chance for admissions at Stanford, but it is a reach. I would be surprised if your chances are all that different from the overall admissions rate.
Stanford is not in the Ivy League. The eight Ivy League universities are not all the same, and are not equal in terms of how good they might be for CS or symbolic systems. The same could be said for other non-Ivy-League schools such as MIT. You really should be thinking about which of these universities are likely to be a good fit for you, and do not just go by overall rankings.
With your stats I do think that your chances at any university in Canada are very good. Again, look for one that is a good fit for you.