From Calais to La ferme de Martine in Montestruc-sur-Gers it's about 1015 km, so you can drive this distance in one day.

There are actually two possible routes when you take the Péage: via Bordeaux or via Montauban. We prefer the route that directs to Montauban: Vierzon, Limoges, Montauban and then to Montestruc-sur-gers. We find this route a lot calmer, with less trucks, and a nicer landscape to drive through.