I am sure that you are correct about there being preemies in Canada too. Because Newborns In Need is a US based charity organization we do not have chapters outside of the US, and not many contacts in other counties.
Often hospitals here have guilds or volunteer groups that work specifically with a particular hospital. You could check with your local hospitals to see if there is a volunteer coordinator who could point you in the right direction or help you connect with others in your area who are doing this already.
Good luck in your search.
Mary/Seattle
...serving God's tiniest children since 1992 through www.newbornsinneed.org