Into Zurich for two nights, then the train to Wengen. Wengen is small and car-free, on the hillside above the Lauterbrunnen valley, and the views are hard to beat. A short gondola puts you up in the mountains, where you can ski between the surrounding towns and eventually ski back into the village. There is almost no restaurant or bar scene, so you eat at the hotel – but the village itself is picture-perfect.
Three nights in Zermatt next, which is a different animal. Much larger, down in the valley looking up at the Matterhorn, with skiing good enough to take you into Italy and back. Plenty for non-skiers too, and far more restaurants and bars than Wengen has.
Then the Glacier Express to St. Moritz. It takes most of the day and it is a day well spent – the scenery is the point, and the train is an experience in its own right. St. Moritz is my favourite town in Switzerland. It has the glitzy reputation, and it also has excellent downhill and cross-country skiing, hiking, restaurants and bars. It sits above a lake, which makes it feel nothing like Wengen or Zermatt. Two nights there, then back to Zurich.
What I'd change
Nothing went wrong, but this itinerary is a lot of train transfers. If changing trains with luggage is not your idea of a holiday, mix in private transfers. Wengen and Zermatt are car-free either way.
I would add a day in Zurich and get out beyond the Old Town. Zurich also works as a base for Bern, Lucerne or St. Gallen.
And take the Muottas Muragl funicular outside St. Moritz for sunset drinks. The views over the Engadin valley and its lakes are worth timing the day around.
