5 ish days in Switzerland

Have you scoped out the travel time? It’s an aggressive plan, but maybe you want that since you’ll relax on the cruise? Cruises often require larger luggage than someone would use for a trip like this, so something to consider perhaps—do you want to lug that suitcase back and forth every day?

With 5ish days go to the Lauterbrunnen Valley only. Mountain valleys are weather dependent meaning you must add an extra night in case of unexpected conditions. There is so much to do in this area i.e., visit Gimmelwald and Mürren, ride the Schilthornbahn cable car and the Jungfraubahn train and walk from Männlichen to Kleine Scheidegg: https://www.ricksteves.com/europe/switzerland/lauterbrunnen-valley.

I've updated my post. I forgot to mention that we are 'basing' in Lucerne and Montreux.

I’d suggest picking Luzern + Montreux, but skipping the Lauterbrunnen day trip OR switch your focus to the Berner Oberland and skip Luzern.

3 nights Luzern > 2 nights Montreux
6/2- Zurich > Luzern - explore old town
6/3 - Boat ride + Rigi
6/4 - boat ride to Fluelen with optional high speed train to Lugano/Morcote OR trip to Pilatus
6/5 - Luzern > Montreux + Lavaux vineyards
6/6 - Montreux > Walk to Chateau de Chillon > boat from the castle to Vevey, Cully & Lausanne
6/7 - Montreux > Lyon

OR

4 nights Wengen > 1 night Montreux
6/2 - Zurich > Wengen - explore the village
6/3- Mannlichen > Kleine Scheidegg + optional Jungfraujoch
6/4- Mürren + Schilthorn + Lauterbrunnen Valley
6/5- Boat ride on Lake Thun to see castles OR boat ride on Lake Brienz
6/6- train to Montreux - walk along the lake to Chateau de Chillon > boat back to Montreux or over to Vevey and Cully for additional sight seeing before returning to Montreux
6/7- train to Lyon