8 Days to Fill After Paris & HOF Tour

How about Brittany and St. Malo? We did a 5 day side trip to Brittany which included 4 nights at a small apartment within the ancient walls of St. Malo and then a night in Carnac where I hired a guide to take us to the neolithic sites since we didn't have a car.
https://janettravels.wordpress.com/category/brittany/
From St. Malo we walked to St. Servan, took the ferry to Dinard and a bus to Dinan. You can do a round trip bus trip to Mont St. Michel but we had done that before so didn't. St. Malo has many outstanding small restaurants and it a beautiful place to spend time.

Thanks Janettravels! We will have been in Normandy and stayed on Mont San Michel on the RS tour but I have always loved the idea of St Malo after reading All the Light We Cannot See. Would it be quite convoluted to get from Lyon to that area?

Pretty sure any long distance trip requires going through Paris. French trains are spoke and hub with changes in Paris.

It's worth while checking sncf connect for options. For instance Lyon to St Malo can be done with one change at Rennes two or three times a day, thus totally avoiding Paris and the change of stations there. Not significantly slower than routing via Paris either.

Either way it's a 5 to 6 hour journey.

People who are used to arriving by ferry at the channel ports, rather than Paris by air tend to have a better grasp of the French cross country routes, as well as the better known hub and spoke routes.

Are there any towns/villages in the more central part of France that anyone can recommend?

I liked Bourges, which you will have seen on the HOF tour, but you're there only one night. I suspect it's worth several days.

I'd also be interested in Dijon, but I've never been there.

Beaune, Dijon, Strasbourg?