Depending on whether you need texting only, or talk & text, or data as well, also factor the duration of your stay.
If you don't need to be reachable at your Koodo number, and your phone is unlocked, you could pick up a local sim card and text people in Canada from there, and browse the web as well. That might be worth it if you'll be there for at least a week.
If you'll be at a hotel with wifi, you could use a VOIP app such as Freetone or MagicJack and call Canada free via WiFi (will show a different number on their call display...the number you'd be getting from the app). Via WiFi you could send WhatsApp messages without incurring roaming as well.