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

That is likely the best route to avoid weather this time of year although Siskayou pass in southern Oregon can be iffy. Listen to the road reports and plan accordingly.
6 hours to Salem is a bit of a stretch. You can easily lose an hour or more waiting in line at U.S. customs then you have to deal with heavy traffic from Everett to Olympia. Same through Portland. Ugh!!! We drove to Palm Springs, don't plan to do it again. Not very scenic for the most part, it gets pretty monotonous especially in the fog.