I'm from the UK. You have studied in the UK, so you should understand that a 3rd honours classification is not so desirable for pursuing advanced degrees. If you haven't done well in undergraduate studies, how do you convince the graduate admission committees that you will be able to do well in graduate schools? However, the grade is not the only factor to determine admission.
Indeed you can give it a try. There're tonnes of universities in Canada. Just don't apply to the very renowned ones like the UofT.