I am planning to be in Paris or Christmas (22nd-29th of December). I am working out our itinerary. There is certainly enough to do just in Paris but we are considering a day trip to Mont St. Michel and a day trip to the Loire Valley. I am especially interested to visit to the Clos Luce in Amboise because of the connection to DaVinci and my son's interest. The question I have is whether we should sign up for an organized tour or whether we should rent a car and drive to these destinations. Any other advice on the experience of visiting these destinations at this time of the year would also be appreciated.