McGill Arts and Arts&Science majors (which includes CS), while costing more than in-state, isn’t a ton more. It is a giant state school, though, though known as the Harvard of Canada (though it’s more like the UMich or UW-Madison of Quebec).
Still, for someone looking to go to an OOS school on a budget, it should be considered.
NMtech grads seem to do well also.
Otherwise, you’d need to earn major merit scholarships. Are you a National Merit Scholar?