Not sure if you've ever been to Montreal, but its a gorgeous city with lots of festivals in the summer (and wonderful food). Its an easy and cheap 1 hour flight from Toronto. Porter airlines flies there from Toronto City Center airport which is right on the harbor- you actually take a ferry to get to the terminal. 9 days in Toronto seems like a bit much to me personally, so a couple days in Montreal could break it up nicely. Just my 2 cents!