Had this same situation occurred on a large cruise ship, it may have meant the termination of the cruise. The logistics to accommodate 166 passengers is much easier than for more than 1,000 passengers on the larger vessels. We applaud Avalon Waterways for making every effort to continue the cruise.
If you aren't familiar with river cruising, we invite you to view our special page about the differences. Warning - once you try river cruising, you might have a hard time returning to larger ships.