Paris to La Roque-Gageac

Via Michelin calls this a six-hour drive, so two days should allow you to make several stops. We did something similar a few years ago and spent the night in Bourges. Other interesting stops might include Chartres, Orleans, and Limoges. We spent a couple of hours at George Sand's house near Nohant, south of Bourges, where Chopin also spent time.

We'd been in Paris for a week or more before this drive, so jet lag wasn't a problem. I know you've driven before after sleeping on flights, so I assume you sleep better on planes than I do. But few people sleep as well on flights as they do at home, and the fact that you've done this before doesn't mean it's "not an issue." A safer alternative, for you and others, might be to spend that first day and night in Paris, and do the long drive south the following day.

Thanks for your suggestions! Your ideas look very interesting. And your sweet comments about sleep were kindly meant but sleeping in first class has never been a problem for us. Obviously if our experience changes, we would adjust our plans accordingly.

Bourges is a nice stop. An interesting city (once the capital of France), a rather impressive cathedral, a nice shopping street.
Further south (and west) is Oradour-sur-Glane, the site of a Nazi massacre, which has been preserved in its ruined state as a permanent memorial. Not a light-hearted stop, but a powerful experience if that's to your taste.