Suggestions for last 4 days of Switzerland Itinerary

How many nights will you be in Switzerland?
When visiting mountains you need to add an extra night. There is a lot to do in both the Lauterbrunnen Valley and Zermatt. Don’t be in a hurry to leave the Oberland so you can visit lesser sights. Can you spend five nights in Grindelwald then work your way to Bern for two nights?

I have a total of 9 nights, and am spending the first 2 in Lucerne, so I am trying to figure out what is the best way to utilize my remaining 7 nights.

We spent 3 nights in Vevey in May , we spent some time in Montreux but preferred Vevey as a base. Different from Zurich and BO. There is lots to see and it’s different from Zurich and BO.

The less moving around you do the easier your trip will be. Especially when hauling luggage.
I recommend spending two nights in Luzern and five nights in Grindelwald: https://www.ricksteves.com/europe/switzerland/lauterbrunnen-valley. Be sure to click on the + sign on the right of At a Glance for all activities to do in the Lauterbrunnen Valley. You can then take a train from Grindelwald to Zurich that only has one transfer and sleep there for two nights. A good day trip from Zurich is Bern.

I'd say three nights in Lucerne. Great idea to go straight to Lucerne from the anirport. Maximize the Alps time. And you can commute easily to the Zurich airport from Bern, if you don't have an early flight. Enjoy this beautiful country. Safe travels!

Thanks to everyone for your replies. Is Zermatt just not worth going to in October or is it just too short of a trip to try to squeeze it in? If it’s worth seeing then I can do 2 nights Luzern, 4 nights Grindelwald, 2 nights Zermatt, and last night Zürich.

Would a better itinerary be to spend 3 nights in Luzern, 4 nights Grindelwald, 1 night Bern and 1 night Zurich (I have to be at the airport in the morning to catch my flight).

Mountain weather is fickle, and going to Zermatt and hoping your day is the clear one is risky. Enjoy this beautiful country. Safe travels.

Would a better itinerary be to spend 3 nights in Luzern, 4 nights Grindelwald, 1 night Bern and 1 night Zurich (I have to be at the airport in the morning to catch my flight).

One night is Bern is not worthwhile IMO. 3 Luzern is enough to give you time to visit one of the big mountains, see the city, maybe take a cruise on the lake, 5 nights in Grindelwald would allow lots of exploration including Interlaken, if you like, and over to the Lauterbrunnen Valley and environs. If you have bad weather in Grindelwald, go to Bern for the day. Last night in Zurich is a good idea.

You’re arriving just as the season is winding down in the Grindelwald area. Depending on whether you arrive early or later this week, some of the most popular hikes mentioned in the forum could be impacted. For that reason, extending your stay in Grindelwald may not be the best option.

The Schilthorn summit, along with the revolving restaurant is closed as of today. You can still go as far as Birg.

On October 20, the Mürren – Allmendhubel funicular closes, meaning if you want to hike the North Face trail, you’ll need to complete the entire circular route without the funicular's assistance.

On October 21, Männlichen and access to the popular Panorama Trail closes, as does the route to Mürren via Grütschalp (you'll need to go via Stechelberg instead). This is also the date that the train from Grindelwald - Kleine Scheidegg closes, as does Schynige Platte.

Grindelwald First remains open until October 28, so you may still be able to hike there. Last week, it was stunningly beautiful to take the gondola up (and not very busy), with the trees at lower elevations displaying vibrant fall colours. There are also other routes that will be open, but your options will be more limited than earlier in the season.

I find Zermatt to be very beautiful at this time of year.

Gornergrat does not close until November 2 to November 7

https://www.gornergrat.ch/en/pages/summer-activities-on-the-gornergrat

You can find information regarding other lifts in the area here

https://www.zermatt.ch/en/Lifts-pistes/Opened-lifts

Also, going to the Montreux area could also be very nice and there are a lot of good options of things to do there. Here is a link to some of their webcams

https://www.montreuxriviera.com/en/Z12305/webcams