I'm planning a driving trip to France in August: starting from Paris - to Nantes - La Rochelle - Bordeaux - Toulouse - Limoges - Orleans - and it ends in Paris again.
The itinerary is like here http://www.voyajo.com/viewTrip.aspx?trip=106745 but without visiting Spain and Andorra. I'll just cut from Bordeaux to Toulouse.
How long can the trip take? Minimum length - if I stop only for staying the nights?
It's a high season, you know, so I need advises how to save on expenses: cheap gas stations, cheap but good restaurants, clean affordable hotels/apartments and so on. Buy the way, which car rental company should I choose?
The points of interest I'll leave for the next stage of planning
A good way to save money while travelling is to eat in restaurants for lunch rather than dinner. Many have lunch specials, so you get to try the same delicious meals for less! If you stay at self-catering accommodation you can make your own dinners.
Firstly if you are looking at saving money and driving in France, why rent a car whilst your over there and add to the expenses? Book a cheap ferry crossing from Uk to France, you can go from Dover-Calais or Dunkerque, there are so many operators so the competition is high and prices are usually cheap, and take your car with you! I'd double check what the laws for driving in France are as I heard they have recently changed. Better safe than sorry.