Paris to Mont St-Michel

Driving in this area is easy (excluding central Paris). Pick up/drop off your car somewhere outside the center (or train to somewhere on the way, do the car there). Do not fly in on a redeye then jump in a car and drive off, it always wakes an adjustment to drive in a foreign country and you don't want to do that when you're jet-lagged and wiped out. Be sure you have an International Drivers Permit (get it at your local AAA office, it's necessary and cheap).

Highly recommend staying overnight on MSM itself (just a few small hotels there, admittedly over-priced, but it's all about location location location) - this allows you to avoid most of the crush of humanity that fills up MSM from 10 am to 4 pm daily. Arrive mid afternoon, watch the human tide recede, enjoy the place for a few hours late afternoon/evening, sleep right there, get up early and enjoy a few more hours, then get away as all the day trip bus crowds roll up. IMHO you can take the train part of the way if you want, but a car is needed to do this right - you'll also want the car for elsewhere in Normandy.

I agree with David's thoughts, tho a less expensive lodging option is just a few minutes from the MSM parking lot and shuttle. Auberge de la Baie. It is a more modest property though our room was VERY spacious and clean. They also have a restaurant and the patrons there seemed much happier with their food than we were with the restaurant on the strip the shuttle runs on. We did basically what David suggests. We went over early evening and got some amazing pictures. The following morning we went over and timed it so that we arrived at the entrance to the abbey (which is a fair distance up the hill). We were among the first in and saw the abbey in relative calm. We left at about noon and had a picnic on the "mainland" with views of MSM. If you do stay off of MSM look for some photo opportunities at dusk across the farmland with sheep in the foreground and MSM in the background. You may also want to get some photos from the bridge to MSM

Please use Google Maps to see how far this is by car. (Like a GPS,you have to add 10% to 20% to Google Maps times.) I think it pairs poorly with seven days (eight nights) in Paris, because of the distance. It is too far to drive after a poor night's sleep on a plane. And it usually requires a rail station change in Paris, if not a change along the way as well. MSM is much easier to do with car, wherever you pick it up. Note that April does not have the best weather, and much of the French coast of the English Channel has weather rather like England.

It is unrealistic to plan one night for both MSM and Normandy. (I assume you mean the D-Day Beaches, as if that were the only thing in Normandy.) That is also a substantial drive on the second day, when you will still be tired from the air travel. Even if you can tough it out, it won't be the pleasure it ought to be.

If you're not going to return the car in downtown Paris, you should think about whether you want to return it at CDG, or someplace else. And don't forget general car rental issues, like IDP and insurance decisions.

I'm giving this advice because we put MSM off until our sixth trip to France, when we barely saw Paris, but did a big loop through the Loire, Brittany, Normandy, and back to fly home from Paris.

Edit: We spent only a half day (by rental car) at MSM, including waiting in line, and that was fine for us. We may have visited Dinan or Dol de Bretagne the rest of the day. We were sleeping in Dinard at the time-not the best choice off-season. Too many seasonal businesses closed.

We went on a tour with Overlord Tours and it was perfect. The guide knew so much history about the area. (We stayed a couple nights in Bayeux), the tour took us to a few small towns with significant history of D-Day. High point was visiting the American Cemetery and being there at 4:00 pm when they lowered the flag and played the anthem - not a dry eye anywhere - very emotional experience.
Then spent an entire day on our own at Mont St. Michel - delivered to the entrance by our guide.

Driving in the area is easy. However, caution about jumping right into a car after an overnight flight is appropriate. One option is to take a TGV train from Gare Montparnasse to Rennes (1-1/2 hours), and then pick up your car there. It is a little bit of a pain to get to that station from CDG, but you avoid driving around Paris at what is often rush hour, and allows you to adjust a little (and maybe nap) on the train. By the way, an international driver's license is not required (watch me get slammed for stating this). A certified translation is required, although I have never heard from a single person on this forum who actually had difficulty because they didn't have one while driving in France. Personally, I carry a non-certified translation that follows the standard format, but have never been asked for it. Frankly, you are more apt to get a ticket from a photo radar which you won't hear about until you return and get it in the mail from your rental car company (along with their added fee). Observe speed limits very carefully. I don't find the speed limits too slow, but any speed over the limit will earn you a ticket.

Thanks very much for all your insightful comments and recommendations. Based on your feedback, I will plan to do an overnight stay in Normandy. Thanks again!

We just did (9-12-18) MSM. Got there to take one of the first shuttle busses to the entrance (9:00 am) and the crown was not bad at all. We brought our lunch with us (I heard the food was not good there) and had a nice lunch seating seating on one of the garden benches with a beautiful view. We left around 1:00 pm.

We took a train from Paris to Caen, and then rented a car to drive to MSM. Stayed the night at MSMS and drove back to Caen and stayed the night in Normandy. The tolls were quite high driving over from Paris; it made sense for us to travel partly by train. We still enjoyed the countryside with the drive from Caen-MSM.

MSM is magical, you will love it! ps, we stayed at a chateau in the countryside in Normandy, it was a beautiful place with so much history. I highly recommend it.

https://www.booking.com/hotel/fr/le-chateau-d-39-asnieres-en-bessin.en-gb.html?aid=304142;label=gen173nr-1FCAEoggJCAlhYSDNYBHIFdXNfYXqIAQGYATHCAQp3aW5kb3dzIDEwyAEM2AEB6AEB-AECkgIBeagCAw;sid=2a4c34fc9e00ba87338137b86607d0d6

Amanda— I’m going to follow your agenda. I’ve already booked a room at the Château. Thanks for the recommendation! Based on all the comments, it’s an unforgettable experience. Looking forward to it! Thanks again everyone. I very much appreciate your insightful recommendations.