Confirm it for France - this is one of those things that could easily vary by location.

I'm pretty sure, but not 100% sure, that Avis and Hertz allows spouses to drive the car for free. I'm very certain in the U.S. because I've asked and done it many times, including in the past 2 months with both agencies. But like I said, it's very possible that France or the EU in general could be different and if you hit that general "chat" thing with someone from Oklahoma City or Dallas, they may not have the slightest clue at all.

I needed to rent a car in the EU once with the intent to drive it out of the EU. It took me forever to chase down exact rules and policies for different agencies. In the end, Hertz Germany worked - but not after lots of conflicting information from different Hertz people: they limited their nicer German cars to EU-only but gave me a small Korean car and told me to go pretty much wherever I liked in it.

Anyway, the lesson learned is that you have to dig, probably translate a French-language website, or talk to someone over there to get a straight answer.