riverboat cruises to France

None for the entire country since all the waterways don't link up unless you go out into the Med, Channel, or Atlantic. Are you interested in a self-drive or a crewed boat? It makes a difference on which company does it.

Viking River cruises does: the Saone and Rhone rivers from Chalon-sur-Saone to Avignon; (travel in either dirction 8 days; the Seine from Paris-Rouen and back to Paris 8 days; or you can combine both cruises into one with a land transfer from Paris to Chalon-sur-Saone

We did the Viking River Paris-Rouen-Paris cruise a couple of years ago when it was Paris-Le Havre. Quite nice if you want slow travel, but don't be like the passengers on our boat who wanted luxury ocean cruising on a riverboat. We docked with Uniworld boats at a couple of ports, so you could check their itineraries as well.