In mid April my sister and I (early 40s) are driving between Mont Saint Micheal to Bordeaux on a Saturday. I was thinking that Tours would be the best stop for lunch? Just somewhere to enjoy the atmosphere and stretch our legs.
And then onto Chenonceau before heading off to Bordeaux. We’re not huge castle/chateau people but when in Rome… right? I’d personally love a smallish city with a lovely afternoon market. Loches caught my eye but I think we’d have to choose between Loches and Tours. Any suggestions and greatly appreciated!
Tours is a bit east of your shortest path. You might consider Niort for a stop -- it's around 4 hours south of Mont-Saint-Michel.
But a warning: markets are almost always in the mornings, wrapping up by noon or 1 to 1:30 PM. Of course, there are evening markets but they're rare. Afternoon markets? Not common. Sounds like a trip to Carrefour, Auchan, Intermarché, Casino, or E Leclerc might be in order if you want to shop in the afternoon.