Since you will be spending July 14 in Carcassonne, don't forget that it will be Bastille Day (Fête Nationale in french)
Every year there is one of the most beautiful fireworks displays in France which attracts hundreds of thousands of spectators.
So: book your accommodation well in advance.
Do not plan to travel by car in the vicinity of Carcassonne that day, you could be stuck for hours in traffic jams.
See details here;
https://www.tourisme-carcassonne.fr/en/highlights/grand-fireworks-display/
If you come from Paris, staying in Dordogne before Carcassonne is in my opinion more interesting and more logical.
You should also know that the Dordogne valley extends well beyond Sarlat and La Roque Gageac which are at its western extremity. This region goes east almost to the center of France.
The Aquitaine region can be interesting for its coastline if you like large sandy beaches and for the city of Bordeaux, but otherwise it consists mainly of thousands of hectares of boring forests to drive through.
Do not confuse the Aquitaine region which officially no longer exists under this name since 2016 with the "Nouvelle Aquitaine" administrative region which also includes the western part of the Dordogne Valley, the other part of the Valley is in the Occitanie region.
Why make it simple when you can make it complicated?
If you have seen travel guides that refer only to Aquitaine, it could be because they are out of date...
If your stay lasts 5 to 7 days it is certainly interesting to follow Judy's advice and find accommodation in a "Gîte De France"
See on the official website:
https://www.gites-de-france.com/en
