Hi Blackwelllarry, last September I did Logroño, Spain to Florence, about 1400kms. I grew up going from San Diego to San Francisco several times a year. So for me it was like old times. For my kids it was hard, but thank God for ipads and headphones.
We did it in two days. The first day was the long haul, from Logroño to Ventimiglia. So basically we crossed France in about 12hrs. The big problem was the toll booths. But the drive was okay.
In Italy it was bad. The highway from Ventimiglia to past Genoa was a scary, expensive and slow.
So unless you want to spend some of your time in Italy, I would suggest taking the train to France and getting a car there. Provence would be a good choice, but to go a bit off the main path I would suggest Languedoc-Roussillon-Midi-Pyrénées, and Carcassonne, and some smaller places like Mirepoix or Foix. There are many Rural BnB type places which allow for day trips.