Our neighbor used to have a Ford 6.8 L V-10 30+ foot pusher and he had only a class C license. I think the class C restricts you to 2 axles and so you're technically a car and can drive in the left lane if you have the HP and the credit limit to do it. Anything more than 2 axles is class B or A...I can't remember which. Most of the RV's are built around regulations so that vacationers don't have to sit with aspiring truckers at the DMV for 6 hours. Regardless of how you get to BC, RV's are easy radar targets
It's a nice drive from SF to the Border. Are you taking highway 1 or 5?