you don't need but you won't be able to leave Thailand before settling an hospital bill and trust me, it is very expensive on case of big accident to be taken care into the good hospitals
Flight tickets hotels etc and maybe in 60+ days this route will be closed or requirements might be higher with papers you might have to get certified or from canada... If you are that short of cash for that risk, you will see that Thailand isn't that cheap anymore if the new tax laws they imposed and health insurance costs etc. IMHO