Driving in Baja is interesting in a car. It can be very interesting in an RV. It has been a while but low sulfur diesel was not available when I drove there. Some one on the Mexico forum section should know if fuel is still an issue.
Follow a semi instead of trying to lead the way over the passes is my advice for first time drivers in Baja.
In winter stay near the Atlantic coast until you are below the freeze zone. Then take what ever interstate has the best weather to CA. I have seen snow on 10 while 40 was clear and visa versa. In June you can go back through a northern mountain route for the scenery.
BTW: My dad was project manager building a heavy water plant in Glace Bay in the mid sixties. Not a fun place in winter.