Route Request Please

We are crossing to Dunerque on April 1 next year and then making our way to Port Grimaud in our Motorhome.  We made this journey last year without enough planning and forethought resulting in a 'could do better' journey.  Passing through champagne vineyards and following the   River Rhone to Avignon were the highlights we are happy to repeat.  The journey could take up to a week with driving approx 200 miles per day on and off toll roads.  Passing through towns is enjoyable but there are an aweful lot of roundabouts in France aren't there?  

Suggestions for a recommended route/routes would be warmly welcomed.

Many thanks