It takes about four hours to drive from Saint-Aignan-sur-Cher to Le Mont Saint-Michel, going through the towns of Amboise, Tours, Château-la-Vallière, Le Lude, Laval, Vitré, and Pontorson.
Somebody asked if Rouen was on the way from Saint-Aignan to Le Mont Saint-Michel. The map shows the route.
We plan to drive back through Nantes. Be back on Wednesday unless we decide to stay an extra day.