Best way to travel from Bayeux to Sheraton CDG Terminal 2C?

You have hit upon the fact that there are no good train connections between CDG and the Normandy region. My suggestion is that you take a train to Gare St. Lazare in Paris from Bayeux. Exit the station and go to the official taxi line and grab a taxi to CDG, Terminal 2C. The cost of the taxi will be 55€. There is an official taxi stand at Gare St. Lazare on Rue d'Amsterdam. Or, if you are so inclined, you can make your way to Gare du Nord for the RER B. There are multiple ways to make that connection including walking 30 minutes or you can try the mass transit options at CityMapper. I'd take the taxi directly from St. Lazare to CDG.

In 2019, we just took a cab from the train station in Paris (Montparnasse since we were coming from Saint-Malo) to the Citizen M Hotel at CDG, which is a few yards from the Sheraton.

Since you're traveling with another couple and have a bit of luggage, it might be worth it to take a car service from Bayeux to the Sheraton CDG. We've been happy with MyDayTrip. Or, you could arrange for a car service from Gare St Lazare in Paris.

https://mydaytrip.com/

If there are four of you, the taxi from Gare St Lazare will be (as correctly noted above) 55€ for all four of you.

It would cost you almost that much for RER tickets for the four of you, so I definitely do not see any advantage in taking the RER.

You could inquire as suggested about car service direct from Bayeux. It won't be cheap, but maybe it will be worth it to you.

Is there any way you could keep the car and return it at CDG? As long as the car is big enough to fit 4 adults + luggage, it should save time and possibly money as well. The drive on 14th August will be extremely quiet because 15th August is off!

It is possible you are looking for trains too far in advance. There are indeed direct trains from Bayeux (or Caen) to Gare Saint-Lazare. From there it depends on how many and what luggage. I travel solo, so I take the RoissyBus from the Opera Garnier (7-minute walk from the train, 13€ per person) to CDG. I as I read from others you have two couples with luggage, one taxi is simple and relatively cheap (55€ for four people. Either way, it is only one change of forms of transportation. Try looking for trains in a few weeks and you will see more options than now. It does not take five hours. Maybe 2-ish for the train, and an hour for either taxi or bus. Don't use Über from Paris to CDG as they don't have a fixed fare and can't use the same traffic lanes as taxis and buses.

Thanks for all the replies. When I mentioned it was over 5 hours by train that was going all the way to CDG with two changes of train. A direct train to Paris proper is just under 3 hours. I also, did consider the possibility of trying to keep the car one more day but I don't think it will hold four adults plus all the luggage. Also, modifying it to a one-way rental might prove too expensive but I will check it out. The private car or van is the most expensive option but offers door to door service. The next best is probably a direct train to Paris plus a taxi (or two taxis if necessary) to the airport.