You didn't give your point of origin. Several other factors should be considered. It is usually easier, cheaper, and less upsetting to take trains out of Paris and pick up the car at the arrival station. Paris has a large airport tax and I've found it easier to NOT drive in and around Paris. Unless you have luggage issues, it would probably also be easier to drop the car off outside Paris. Traffic around CDG has been perfectly hideous of late.

2)Thanksgiving weekend can be a great time to fly. I always fly Thanksgiving day, as the loads tend to be lighter on the day itself. Fares are also often more reasonable, although that probably won't show up just yet.

3)The Salon des Vignerons is super, if a little bit confusing. The vignobles aren't exactly organized by type of wine produced, region, alphabet. See if you can find a listing of exhibitors on line in advance. This thing is usually in one of the halls at Porte de Versailles and fairly large. Also, take a water bottle. There are only 2 very small refreshment counters, and the lines are often quite long. Also take a small dolly(they also sell them there)if you expect to buy more than a few bottles. The sellers will cheerfully package things up, but wine gets heavy fast.