Whilst I have not actually travelled the whole of this route, but I have travelled from St Jean du Luz to Zaragoza and onward to Valencia. I would have thought you would be pushing it to travel from Santander to Zaragoza, seeing you arriving in Spain at 1pm, say 2 pm before you clear the port, unless ypu are happy driving at night. The distance is approx 250 miles depending on which web site you look at, my satnav says 250; the route is predominantly toll roads. The site at Zaragoza is relatively easy to find and is an excellent municipal site. The route from Zaragoza to Valencia in on toll free autoroute quality roads, the distance to Valencia is approx 200 miles. Hope this helps.