Three days in Switzerland

I love Zermatt, and have been there for both skiing and hiking. BUT... Zermatt is 3 hours by train from Bern and 3 1/2 hours from Zermatt to Zurich. The Bernese Oberland Area - Lauterbrunnen/Murren/Grindelwald/Etc. in the mountains south of Interlaken (which IS very touristy) its much nearer. 90 minutes from Barn to Lauterbrunnen and 2.5 hours from Lauterbrunnen back to Zurich.

Check out travel options on sbb.ch the Swiss rail website.

You might think of Luzern/Lucerne. There is plenty to do. I've heard Zermatt is nice, though I've never been. I can tell you that Luzern is one of the most beautiful places I've been in Europe. Its close to Bern and Zurich. You could stay in Luzern the night before your flight. Whatever you choose, spend your entire time in one location.

Zermatt is 2¼ hours from Bern. But if you think Interlaken is "quite" touristy then Zermatt is 98% touristy!!! The village is about 1¼ miles long and much narrower, so what "Zermatt touring" consists of isn't clear - cars aren't allowed in Zermatt so you won't be alone.

Interlaken isn't so much touristy, more full of tourists on the move. Not so many stay there, or even hang around for very long.

You (like many, many people) have missed a gem - Basel itself has a very nice old town and plenty of museums etc to visit so don't be in a rush to leave. I prefer it to Bern.

I can understand that you would want to get somewhere close to the mountains (which Basel can't claim to be) but Zermatt is a long journey for mountain views. Interlaken was a sensible direction, if not the best choice, consider staying with the route but continuing to Brienz or Meiringen which are prettier (Brienz has good sunset views across the lake) - the train from Basel at 15:58 takes 2 hours to reach Interlaken Ost and then it's another 20-30 minutes. Stay the two nights there and then on day 3 after breakfast go to Luzern (which is on the logical route to Zurich) and spend the day there before an evening direct train to the airport, twice an hour in about 1¼hours.

Honestly, if your time is limited I would skip Bern. I would much rather spend time in Lucerne.

October in Zermatt is between seasons. Too late for hiking due to possible ice and snow, and too early for skiing. As was suggested, Luzern is your best bet with an easy 1+ hour direct trains to Zurich airport.

You can certainly get around Zermatt easily without a car considering it's a car free village and you're not allowed to have a car there :)

Anyway, with only 1 full day, skip Zermatt. Zermatt, Luzern and Interlaken are all equally touristy so if you're trying to find somewhere not touristy, you need to look for somewhere not on all the highlight lists. If you're okay with touristy, then hear to Luzern for 2 nights and do a boat ride on Lake Luzern + Rigi to experience the mountains OR go to somewhere like Wengen for 2 nights and experience staying up in the mountains in a car free village.

I always struggle with the term, "touristy". To me, that means mini golf, etc. Think Wisconsin Dells or Hill CIty, South Dakota. If touristy means, crowded, yes, Luzern gets a lot of tourists. There is a reason some places get a lot of people. For myself, I do keep an ear out for less crowded places, but some places, are just too lovely to miss. In those situations, it can be helpful to do some strategizing. For example, I rarely daytrip to crowded places. I like to enjoy the places before the crowds infiltrate the city. I also, try, as much as possible to visit at slightly less busy times of the year. I don't think October is as busy in Luzern as other times. For this scenario and time of year, Luzern is a good idea, because its close to Basel and Zurich, and if it is transitional weather, there would be more options in Luzern than Zermatt.

I always think of Interlaken as a transportation hub and less so a destination.