If you're in the New Unlimited Plan, the Go Unlimited Plan, or the Beyond Unlimited Plan then no. Your data will throttle after a half GB each day (that's in order to keep the price down so it can be offered as a free feature on those plans. But as far as charges are concerned, you're good.
I forgot to add that includes Mexico travel as well. If more than half your usage is in Canada or Mexico in a 60 day period the usages could be reduced or removed. It's not designed for you to live there.