Well,
The best solution is to find a Publisher that has license agreements in other countries such as Canada. You will have to do some research and will have to sign a Publishing Agreement but it is the best way. If I found an Artist that wanted to release some of my songs in another country I would only do it thru a U.S. Publisher. All countries that signed the Berne Agreement will have reciprocal agreements so you will receive any royalties due after other splits with the Publishers. Most first world countries including the United Kingdom have signed the Berne Agreement. Good luck.

Ray E. Strode