Nightjet from Zurich to Vienna

Not between Zurich and Vienna, but I have from Zurich to Prague, Venice to Vienna and Vienna to Krakow. You’ll like having your own cabin and restroom.
Some people are unable to sleep on a train even if lying down, so I eat a heavy meal before getting on. Once on the train I take off my makeup, brush my teeth (don’t drink the water) and wash my face before climbing into bed and read for about 30-minutes before turning out the light. I’ve always gotten enough sleep to make it through the next day.
Thirty minutes before arrival your conductor will knock on your door to wake you and even bring you coffee to go.

Last time I went on a night train, I went to a cinema and saw a movie to kill time before the late departure.

We took the Salzburg to Zurich Nightjet years ago. It was fine, and I got plenty of sleep.
Last time I was at the Zurich train station I had to use up several hours due to rain. There is a huge mall connected to the train station so there were plenty of stores and restaurants to visit.

As the previous reply indicated, you could do some shopping in the huge Shopville mall which is in the Zürich station https://www.sbb.ch/en/station-services/at-the-station/railway-stations/shopville-zuerich-main-station.html . I can't remember what the luggage storage options are in Zürich station, but another possibility would be to take one of the bus tours and have a look at various parts of the city and the history. The bus tours often leave from the Sihlquai Coach Parking which is about a five minute walk from the station (very easy!). This will provide some ideas. There are also boat tours available.

There is the Swiss National Museum across the street from Zurich Hbf is worth an hour or 2 if Swiss history is of interest.

Another option is: rather than kill time in Zurich, kill time in some other spot between Wengen and Zurich. You could travel via Luzern and experience the beautiful train ride between Interlaken and Luzern and spend up to 6 hours there before heading to Zurich Hbf is which just a bit more than 1 hour away from Luzern.

Thanks, these are all great suggestions. Seems for sure they would have storage for luggage in Zurich and perhaps Lucerne if we stop there on the way.

yes they have - downstairs in the middle of Luzern

There is loads of storage at the Zurich station, and loads to do in and around the station. Just before CoVid in 2019, we did a stopover in Zurich from Innsbruck. Enjoyed a few hours, grabbed some lunch, walked around and window shopped. Zurich is very expensive so beware. Having been several times, we find Zurich quite lovely. We have been on the Nightjet on several occasions (not to Vienna) and pretty much always slept like a baby. Private First Class is the way to go.

One tip for your arrival in Vienna - your Nightjet sleeper car ticket entitles you to access the OeBB lounge at the Vienna train station for up to 1 1/2 hours after arrival. I found this really useful when I took the night train to Vienna from Zurich - clean bathrooms, free coffee/snacks and wifi. It was nice to have a calm place to go freshen up and get organized since I couldn't check into my hotel right away.
As for Zurich train station, you've had some good suggestions already. Bern is also a convenient and worthwhile stopover option. You may also want to wait and see what the weather is up to and decide based on that...

How incredibly helpful you have all been! Thanks. I like the idea of seeing what the weather is doing and then deciding. And nice to know about the arrivals lounge in Vienna. Thanks you all!

There are people who make a living from Youtube videos of train trips (yeah I know, too cool).

Sleeper trains are a common topic, especially on that route, just do some searching and you'll find tons of videos.

And I wouldn't be surprised if a guy named Rick Steves has a section on Zurich in his guidebook.