Is it too late to get a DDay Beach tour, solo traveler, for March 26/27?

You should be able to book one solo as part of a larger group.
Did you try this company?

https://www.overlordtour.com/

The tours more commonly start in Caen or Bayeux.

Believe it or not just like going to Chenonceaux you can do your own tour without a car to certain segments of the DDay Beach area.
I went on the public bus with other cash strapped travelers without cars from Bayeaux to the American Cemetary and toured Omaha beach. You just have to do your own research of the area since you will not have someone dramatically narrating what happened where. But you have more time and space to yourself. The Omaha Beach is intriguing given the war history and the serenity you feel there today. Just let me know if you want to know how.

There are companies that do small-group tours in vans; you don't have to use a private guide unless you want to (and can find one available). I used Overlord last year and was very satisfied. Another company that gets positive comments here is Dale Booth. I recommend a full-day tour from Bayeux.

I don't know that those companies have really frequent tours at this time of year, but they may. You'll need to spend the night before the tour in Bayeux unless you want to try for a tour from Paris (but that makes the tour shorter). If absolutely essential, you could probably get a train back down toward Paris after the tour, but it might be tight, because you'd probably have to go back to your hotel to retrieve your luggage. It would be great if you could manage 2 nights in Bayeux. There's a good World War II museum, an historic cathedral, and the Bayeux Tapestry.

In any case, check with Overlord and/or Dale Booth.

Description of Overlord's tours. (I took Tour 2.)

This seems to be the contact form. Give them the date(s) you have free for the tour and list the tours that would be acceptable to you.

The tour cost last year was about 100 euros.

Thank you both. Jazz, I thought the problem with taking a bus to D Day beaches was that they run infrequently in March. I am not opposed to self-touring and history is very interesting to me, so really no problem brushing up beforehand; my main concern is transportation without a car.

Acraven, I will be coming up from Montpellier. My initial outline of a plan is to spend one night in Loire Valley, on nighht in Bayeux, then leave for Paris from Bayeux the day I fly back home. I have not sketched out yet whether this works time-wise. It may be such that I have to simply choose between Loire or Bayeux so my time is not so crowded between them.

Part of my objective was simply to be much closer to Paris on my departure day than I would be if I stayed in Montpellier until my last day. I don’t want to go all that way on the TGV before I even get to CDG to fly home.

It's never too late.

www.toursbylocals.com

I'm unclear on your exact timing, but if you're heading back to CDG for a transatlantic flight, I wouldn't want to spend the last night in Bayeux. The train trip takes over 3 hours and involves changes--sometimes requiring a cross-town transfer in Paris via Metro or taxi. We have someone on this forum who has posted about being on a TGV that was delayed about 5 hours, causing many tourists to miss their tightly-scheduled flights home. Check the schedules on the Deutsche Bahn website and see whether it would be possible to head back to Paris right after a Normandy tour so you're there the night before your flight.

Poo. I didn’t realize Bayeux was that far from Paris. I thought it was more like an hour. My original plan was to go back to Paris two days before my plane departs, doing things in and around Paris. This would mean I was not in much danger of missing my flight on departure day. I might have to go back to that plan.