Help with 10 day itinerary (5 days in Interlaken)

You could take the lake boat to Brienz, very short walk to the Rothorn Bahn, and take that up to the top. Beautiful views, very nice trip. But you should verify they will be running, as the tracks were very damaged in last year's flooding/landslide. I'll be there in a month, out hotel room looks out at the Rothorn Bahn tracks. If you'd like a meal in Brienz, the Steinbock restaurant is a short walk and is very good.

Your list is plenty for 5 days

1 day - Mürren, Gimmelwald
1 day - Wengen, Grindelwald
1 day - Bern
1 day - Luzern
1 day - Zermatt

Personally I think that’s a bit much and I’d move to Luzern after Interlaken and do Bern and Luzern from there. If you do, you could add a day on Lake Thun & a day on Lake Brienz to your time in Interlaken.

No trip plan survives contact with the Swiss weather.

What you should do is just inquire as to what are the things you can do in the area.

Then on day one:
- Look out of the window.
- Check the weather forecast.
- Decide on what you'd like to do.
- Go out and do it.
Day two, three etc...: Just repeat.

5 days in Interlaken is about right. Giessbach Falls and Aareschlucht are near Brienz. One night in Zermatt is fine if the weather is good. For flexibility, consider staying between Visp and Sion 3 of your second 5 days..

Thank you so much everyone for the advice. You've given us some great ideas and we really appreciate the help!