Allan, of course every barge company will be different. Some are full charters, some are by cabin. Some include all meals, some you are on your own for lunch or dinner.
But, many years ago we booked 2 cabins on a larger barge in Burgundy. There were a total of 16 or 18 passengers on our trip. Every day a different excursion was offered in the morning- a winery tour, a castle, a walking tour of Beaune... Every afternoon there was an organized walk to a village, a church, through the vineyards... Participation was totally optional. We could also walk or bike along the canal paths and meet up with the barge along the way. Meals were wonderful and the chef didn't hesitate to prepare something different if the menu wasn't to your liking.
Yes, you don't cover a lot of territory. But you do have the opportunity to discover an area in depth. It was slow travel, but our week was anything but dull.