At the end of the day, you are the only one who is genuinely interested/invested in ensuring that your ass is protected with a rental vehicle. Rental insurance is one of the things you should neveral generalize; always investigate and fully understand your specific car rental. Never trust that just because you're in province/state X that the rental vehicle must adhere to the local insurance requirements - rental companies often register vehicles outside a specific province/state (because its cheaper) and the liability limits may be very different. Vehicle rental companies generally offer add-on insurance - if you want to go this route then fully read the details and ensure that you are satisfied that you're adequately covered; this is particularly important when you're out-of-country.
Personally, when feasible, I always pay for my rental with a credit card that includes rental insurance that I have confirmed adequately covers me. As a backup, my personal vehicle's insurance also includes full rental coverage. In all cases, make sure to speak with the insurer ahead of time and discuss the limits of the insurance and what their procedure is if you get into an accident, particularly when you're out of your home province/state or country.