driving in France

I think it's very doable, though a bit rushed for my taste. I don't have a map but it shouldn't take more than a few hours to drive from Orly to a place like Blois on the Loire, and you can see at least a couple of the chateaux east of Tours (Blois, Chambord, Cheverny, Chenonceau, Amboise, others). If you give yourself part of a day to drive up to St. Malo you should have the rest of the day there, and maybe the next day for Mont St-Michel. But you'll need time to return the car to Orly unless you can live with a drop-off charge for somewhere else. Driving isn't difficult and the major highways are very fast (though can be expensive).

Thanks for the wise advice. We may opt out of driving and take a guided tour instead. Sounds a lot easier.

If you go through Autoeurope.com, you won't have a drop off charge if you don't return the car to Orly.

I would say that the drive is doable. Having time to actually see things in each location is debatable. You are looking at over 12 hours of total driving time from Orly to Amboise to Mt St Michel to St Malo and back to Orly. Depending on when you arrive and how long it takes to get the rental car, you could end up not getting to the Loire valley until late in the day. By the next afternoon you'd have to be heading off to MSM, and then the following day back to Orly. Not sure what the tour options are you are looking at, but it might be better than trying to do all this yourself in three days.

Decided to do the guided tour thing this time.