If you cross into Canada, your policy will cover you throughout all Canadian provinces and territories, and between all ports.
If you’re crossing south into Mexico, your policy will protect you if you’ll be traveling within 75 miles of the border for a maximum of 10 days on each separate entry or trip.
If you’re traveling deeper into Mexico (or for longer than 10 days), any accidents you’re involved in will be subject to Mexican law. So plan ahead, and familiarize yourself with Mexico’s state and national insurance requirements.