Send SMS through internet to another country
I don't know about Canada, but here in the UK some carriers have apps that let you use your WiFi connection to send texts and receive using your normal phone number. I'm not sure about using this overseas but you could probably use a proxy (like Hola) if this is blocked. Even if an app exists but you cannot receive texts with it then this is generally free when roaming because you have no control over who sends you an SMS.