Roger did say on the majority of the canals. Minervois is a very small firm operating on one section of canal (Midi/Garonne) and they certainly don't operate off it.
The move of this topic off narrowbeam vs widebeam is my fault - as I thought Dutch barges should be considered as well, especially if the OP was considering cruising in Europe. It was not meant to denigrate wide beams which have their place - which IMO isn't in Europe unless you are content to potter up and down one of the smaller and quieter canals. This is not to say they can't travel further, some do, but they are certainly not best suited for that.
Peter