Just a note that 4 years ago, one could not buy tickets on the night train from Munich to Croatia online. Had to be through a travel agent. Hopefully things have changed. And hopefully you won't have any rail works that results in you being booted off the train in the middle of the night.

FWIW, I think the private washing facility is just a sink.

The change in Ljubljana is also brief and there were only 2 trains a day off season to north coastal Croatia (Rijeka - former lair of the imperial Austrian fleet) so hopefully frequency has improved. These trains weren't very nice.