We are doing the best of Germany-Switzerland-Austria tour next summer, and spending one night in Wachau Valley. Where does this tour typically stay?
I would reach out directly to the Rick Steves office. Hotels change. And they may not even have it confirmed at this point. They will have accurate information. I'm assuming it's not your first or last night; as that should be listed in your portal on the itinerary. Every first and last hotel is included so you can plan to independently extend your stay if so desired.
Enjoy your tour!
The RS Tours office will let you know all your hotels 30 days before your tour begins.
I seem to recall something about Melk or Krems an der Donau as the base.