We haven't done such a cruise (yet), but on our last Caribbean cruise, we were seated with several older couples who absolutely raved about Peter Deilmann river cruises. They're based in Germany and do all major European rivers. I'd check 'em out.
I have sailed the Mozart of Peter Deilmann from Passau, Germany to Vienna, Budapest and back. It was a wonderful experience. The ship is definitely 5 star rated, and the food and service were outstanding. The accommodations were wonderful, and about half of the passengers on our cruise were Americans, with the rest European, mostly German speaking.
I would definitely recommend this cruise line . The 5 star Cezanne, of Peter Deilmann, sails in France.
Happy Cruising, Ginnie
We took the Viking Pride Budapest to Amsterdam it was good. I think all the river cruises are about the same. The cabins are small, We book the best they have and still small. All the tours are in the price no planning shore tours just go with the group or stay on board. It is a good way to see Europe!
If you click on Cruise Lines and go down to Viking River cruises you can get a lot of info