So you'll need a passport to enter the foreign regions beyond the outskirts of Toronto. And outside of Toronto uses a different currency so you'll need to exchange what you have. 🙂
Of course the service will work. Even with an older provincial plan. It will still let you call the province you're in. Data and text are nation-wide as is your likely Canada-wide plan. Canada goes from the Pacific Ocean to the Atlantic Ocean and to the Arctic Ocean.