We are taking our family (3 children) from Salzburg to Paris. We considered flying and taking the train. With connections, it's a full day. Since we already have a rental car, I am considering driving the distance. Do you have any recommendations of great locations we should stop at in between?
If you want to have time to stop and see anything you'll need 2 days; it's a good 11 hours if you include pit stops for gas & food. Half way on the most direct route is Strasbourg. You'll be passing by the Romantik Road, Black Forest, champagne country, etc...... depends on your interests where to stop. If your kids are very young you could end the drive at Disney Paris, turn the car in there, treat them to a day at the park then take the train into Paris.
The shortest route is Salzburg-Munich-Augsburg-Ulm-Stuttgart-Karlsruhe-Mannheim-Kaiserslautern-Saarbrücken-Metz-Paris. How old are the kids? You'll be passing by Legoland Bavaria, the Porsche and Mercedes museums of Stuttgart, the tallest church clock tower in the world (Ulm), Heidelberg (castle and old town)... Once you cross the Rhine river by Mannheim it's about 5 more hours to drive...
I can't help you with locations, but I did want to mention something else about driving from Austria to France. There is usually a hefty charge for picking a car up in one country and dropping it another. You might want to check into how much more it will cost (also factoring in fuel and tolls). Since driving will also take all day, you might decide that you want to take the train after all.
How long do you have for this leg of the trip? Where do you plan on dropping the car off in Paris? How old are the children? Come back with some more info so we can help you. Sounds like you have a great trip planned with the family.
I would only stay somewhere inbetween if you can stay at least one night. Maybe two. Otherwise just take the train, if you're willing to leave very early (at 4:30 a.m.) you can be in Paris a little after 12:00 p.m. (although double check that the first leg of that ride, a night train, has compartments available, otherwise you're paying for a couchette for a 2 hour trip, not a good deal.) There's also a train leaving after 7pm that gets you into Paris in 8 hours. Plenty of time to enjoy the evening.