I have chosen these towns as planned stopovers & want to stay 2 nights in one from the list, others get one night each. Give me your choice/reason/s for a 2 night stop from this list:
Amboise, Sarlat, Carcassonne, Arles?
Travel begins with one night in Bayuex, then proceeds from north to south, all via rental car.
If you have another town choice that's nearby to one or more of these towns please advise where & why you'd pick that town instead? Thanks for your thoughts!
Provided you have a few hours of daylight left upon arrival, Carcassonne and Sarlat are definitely both one-nighters. Amboise is just about as close, but I just don't like it, so judge accordingly. Arles has enough to look at for a couple of days.
Now, if you chunked Sarlat and switched to Les Eyzies, you'd be is business for two nights and could reduce Arles to one.
I was just in all of these towns in June. Carcassonne, just for La Cite' and Amboise, for the Chateaux, can be ok for one night. I would skip Sarlat for Beynac unless you have a good reason to go there. It really doesn't matter where you stay when it is just for a night as you are not using it for a base or exploring it in depth. Arles is a bigger town than the others with more to see and do. Try to stay the weekend there so you can go to the Saturday market.
One night in Carcassonne has been enough for me before; La Cite is very compact and the church and chateau within the walls don't require much time. I would want to visit at least one good market day, wherever it fits in. Sarlat also has a wonderful market on Saturdays or Wednesdays, and p. 488 of Rick's France book lists other market days in the Dordogne.
FYI, the big market day in Carcassonne is Saturday morning on the main square in the bastide, 16th century part of the town down the hill and over the river from La Cite.
We have stayed in Arles (and also St.Remy). You might like Arles. It is a small town with a well preserved Roman amphitheater as well as other ruins and historical sights. It is driving distance to many other sights and towns such as Pont du Gard, Uzes, Orange, Avignon, Les Baux de Provence, and many more. An interesting area to visit is the Camargue, a natural preserve where you can see pink flamengos and other wild life as well as beautiful beach in Saintes-Maries-de-la-Mer. You don't say where you will be the night prior to the two in question but depending on where you are you might be able to drive through the Camargue on your way to Arles. In and around Arles you will have more to see and do than you can fit into your time there.