You can absolutely take a Mexican plated vehicle into Canada. Our friend, who lives here 90% of the time, annually drives his Guerrero Mexico plated vehicle back to Canada for part of the summer. He does his thing, then drives back.
We did exactly that into California when we relocated permanently to Mexico. We kept our Mexican drivers licenses handy but in almost three months, we were never stopped and questioned. When I drove it across the border into the US, they simply scanned my US passport and waved me through. I was also pulling an empty cargo trailer, also with Mexico plates.
I have to agree with the above posters. You might be able to get away with having the RV in someone else's name, but if there is a problem, I'd still be extremely worried about the insurance situation. I never play to spend time in a jail in any country, and it could easily happen if the insurance isn't right.
Good Luck.
