Help with Geneva to Milan Itinerary

5Terre is definitely the outlier, here not well connected to Chamonix. Lauterbrunnen as a day trip from Montreux? Spend
a couple of nights there instead of 5Terra. Be aware possible Covid hassles increase with each country you visit, things are getting better hope you have no issues.
Brad

I suggest you skip Chamonix and substitute Murren or Wengen or Lauterbrunnem in the Berner Oberland region instead. Forget Cinque Terre and Lake Como and save those for a longer trip to Italy.

• Day 1: Land in Geneva and train to Montreaux.
• Day 2: Montreaux
• Day 3: Take the Golden Pass train to Interlaken. Train to Lauterbrunnen. Stay in either Lauterbrunnen, Wengen or Murren
• Day 4: Stay in the Alps
• Day 5: Stay in the Alps
• Day 6: Stay in the Alps
• Day 7: Travel to Milan
• Day 8: Milan
• Day 9: Milan
• Day 10: Fly home from Milan

I think you will enjoy your trip in Switzerland and you won't spend so much time traveling.

Too many countries, too few days. Even tho we all hope the covid situation will be improving, you are crossing too many borders. Who knows what the covid testing , tracker forms, and changing mandates will be? It's a lot to keep up with. We went to Switzerland last Sept, 2022, it was an incredible amount of prep work just for one country. It was a great trip, but it was work.

Cut out France, cut out Cinque Terre, spend as much time as possible in the Berner Oberland and Lake Como, and just one night in Milan. However, you have three nights in Milan, so perhaps you have a reason???

Good luck and safe travels!

Chamonix to Como is quite cumbersome. It involves buses, or a lengthy detour thru Switzerland. The nights of days 2-3-4 will be better spent around Lauterbrunnen.
And I concur with the others: a round trip to the 5 Terre from lake Como is not ideal.

Threadwear’s itinerary makes the most sense but also depends on what you like to do. Long hikes? Easier walks? Just hanging in cute villages?

May can still be chilly and snowy at elevation. Exactly what dates?

3 nights in Milan: do you have specific sightseeing objectives?

A few observations/suggestions:
Visit the Cinque Terre in conjunction with another trip due to transportation logistics (we haven't been to the CT but want to go),
Your plan for the first 2 nights in Montreux with Chillon is good (it's what we did),
Consider shaving 1 of your 3 nights off Milan but make sure to visit the Duomo and The Last Supper (we like Milan and have spent 1 night there on 2 different occasions),
With 5 nights left between your stays in Montreux and Milan you could visit the Lauterbrunnen Valley area (stay in Wengen or Murren) for 3 nights and then take the train via Milan to Varenna on Lake Como for 2 nights (we had 4 in Wengen and 2 in Varenna - loved both),
OR you could head to Chamonix and then on to Lake Como and divide your nights based on transportation or pick another place between Chamonix and Milan to visit (we haven't visited Chamonix so don't know the logistics but our friends love the place),
You could probably get by with shaving a second night off Milan if you can get there early on the day of your first night and this would allow you to stay 2 nights in Chamonix, double back to Montreux to take the train to the Lauterbrunnen Valley for 2 nights, and then on to Varenna for 2 nights (a lot of traveling and you may be able to research a better transportation plan - or someone else will post one on this thread).
Hope this helps and enjoy your adventure!