IS THERE A BETTER ROUTE TO GOLD CANYON AZ from Vancouver?

I think you have a good plan. I don't remember the route (others will know), but i would stay away from driving through LA if possible. I would also keep a close eye on the weather when traveling through southern OR (Ashland area) and into northern CA. Once you get to Redding, you are good to go. Also, CA laws put a max speed at 55 MPH for vehicle with more than 3 axles or towing anything. The CHP loves those of us in the NW.