I've done Calais to Valencia with a single overnight stop in my old T4 California - including collecting a friend from Paris Orly en-route. We stayed the night at an Airbnb in Millau (within site of the amazing Millau viaduct). The timings as I recall were a 6am crossing on the Tunnel and I easily got to Orly for 10:30am. We arrive at the Airbnb at about 6pm, and we were on the road again for 9am the next morning. We stopped for breakfast, lunch and snacks and got to Valencia in plenty of time to check in for the 10pm ferry to Ibiza.