lioncar; I’ve never heard of or met an American who came to Canada with a special “Canadian” insurance card. The policy itself will say where the insurance is valid, and it will in nearly all cases be Canada and the US, and specifically EXCLUDE Mexico for which seperate insurance is needed, for good reason. Car insurance is a provincial jurisdiction in Canada, and there are fines for not having valid insurance in most provinces.
Canadian customs want you make sure you are the valid owner of the car, and your ownership certificate will be important.
One of the best times I had was when a blizzard hit Ohio and I had to return from Ontario. I got about half way and decided it was time to pull off and find cover.
Been in a couple of those storms where you just can’t go any further…and you have to find a place to stay…One was a weekend trip to visit my girlfriend who was attending SUNY Oswego college in Oswego NY. Storm started on the thursday night I drove up to see her…Finally ended Sunday…Couldn’t even move until Tuesday…When storm was finally finished - over 90" had fallen. My 72 F150 was somewhere in the dorm parking lot buried under the blanket of 8’ deep snow.