I had my 68 280 sl transported in a closed truck from Spokane, Washington to Port Lambton, Ontario, Canada in December, 2020. My situation was a bit different as I wasn't transporting it to sell but for repairs at the SL Barn. It still required the services of a Canadian customs broker, and the way it went, the US carrier delivered the car to a storage facility owned or controlled by the company that I arranged the transport with. The car sat there for about three weeks before a Canadian transport vehicle picked it up in Pt. Huron, Michigan and drove it from there to Port Lambton. During that waiting period customs checked the title and made sure the car wasn't stolen although it certainly didn't take that long to complete the search. The delay was the result of the company I signed up with waiting to fill a closed transport vehicle on the Canadian side. Fortunately I wasn't in any particular hurry as I don't drive the car in the winter in Spokane anyway. So, again, I don't know how helpful this is to your specific situation but it certainly is possible to get cars across the border now, you just aren't allowed to drive them across yourself.