Montreal in the early autumn is hard to beat. The summer crowds clear out, the air gets crisp enough for a light jacket, and you can spend your days walking the cobblestones of Old Port without elbowing anyone for a table at a local bistro.
A typical trip runs about $1100 for flights, a place to stay, and food. When you are ready to book, spreading that cost out over time makes the hit a lot easier to handle.
Keep in mind that the 0% intro APR for 15 months on purchases and balance transfers is a deadline, not free money. If you still have a balance left when those 15 months are up, interest will start charging on what is left over.