On this site by Michelin you wiil find the route from Dover to Cantecor. Just change your departure address and leave the destination unchanged. You will be guided to arrive right to our front door. On the planner text at the bottom it is mentioned to turn left for La Madeleine via the D83Bis. Recently this has been changed to D250.
For GPS users:
City : Montpezat de Quercy
Street : 240, Chemin de Cantecor(ps) or Lieudit La Madeleine or D83bis
or use one of the following coordinates:
GPS digital : N 44,28227 - E 1,48055
Coord.: N 44°.16'.67'' - E 1°.28'.49''