I posted about our trip across Europe when we returned with the dogs. It is easy across France and there are plenty of hotel chains,FI,B and B, Campanile, Mercure etc or the farmhouses sometimes advertise chambre d'hotes which is when they let accommodation out on the farm.If you are going through the Frejus tunnel it only takes about twelve minutes. Once through the tunnel if you need a hotel for the night Italy tends to have individual hotels. At Torino(Turin) there is a good stop for the night at Rivoli,the Davide Hotel, and the owners brother owns a pleasant restaurant nearby. Also in the Asti area is a village called Bricco Barrano where the Cascina Bella Vista is very pleasant and run by an English couple.
When we visited Rome we did not even attempt driving in the city. It is best to stay outside the city near a train station and go in by train.Once in Rome there is a bus which travels a circular route and you hop on and off of it on the one ticket at the tourist spots.II Colle degli Ulivi is one place to stay outside the city. We also stayed at the Villa Vecchia for a night(Frascati area)nice sparkling white wine!I could imagine the Sopranos holding a wedding there.
Florence is also hard to drive around and we parked in the hotel car park. There is so much to visit in Florence and it is fascinating walking around. I especially enjoyed the Pritti Palace with the Boboli gardens.
When going on the ferry to Greece it is easy.It takes about eight hours to drive across Greece. We stayed at Kavala (I think it was the Egnatia hotel).There is also the Imaret which is an ottomman style hotel.As usual parking is a nightmare.Very pleasant there with a lovely view of Thassos from the room. You may not need to stop in Greece and make it over the border to Turkey. I wonder how the present situation in Greece would affect anyone visiting? We visited Gallipoli not Istanbul and that was a moving experience. It was easy to catch a ferry across the Bospherus and quite a pleasant little trip (tea in plastic cups and men selling perfume).
We are driving to the west coast of Ireland today with the dogs so they are still travelling!:D
We visited Istanbul on separate occasions and did not drive. We flew in and used the taxis and excellent clean metro system for sightseeing. When visiting friends there they drove and the roads and drivers are quite daunting.