Advice for town/city stay and transport

If you have activities planned at Grindelwald and First, and the Jungfraujoch, why don't you stay in Gridelwald?

You probably save the most money by getting Half Fare cards for 120 CHF each. That covers 50% of the trip to the Jungfraujoch, unlike the Swiss Travel Pass, which only covers 25%. All trains in Switzerland are pretty much "buy a ticket and hop on the next train" basis. Trains are at least once per hour in Switzerland, and often every 30 minutes.

You'll save money buy buying the tickets from Switzerland to Florence and Rome as far in advance as you can. Your best price will probably to buy at www.trenitalia.com. But they will only show trains from Spiez that are direct to Milan. So you would still need to buy local tickets from Grindelwald to Spiez. www.sbb.ch/ will sell you tickets all the way Florence and account for the Half Fare. Check who gives the best price, keeping in mind that Trenitalia will be priced in EUR and SBB in CHF.

Hi Rob, that is a very short amount of time to try to see Switzerland, plus Florence & Rome. Looking at the basic travel times, this is what your itinerary will be. You would only have one full day to see Florence and an afternoon/evening to see Rome.

Day 1 & 2 (with time zone changes & flight): Fly to Zurich & 3-hour train to Wengen.
Day 3-4: Jungfrau/Wengen/Grindelwald
Day 5: 6-hours train ride to Florence
Day 6: Florence
Day 7: 1.5-hour train to Rome
Day 8: Fly home

During our trip to Switzerland where we went into Italy, we flew into Zurich, stayed in Wengen 3 nights, took the train to Stresa, Italy for 2 nights and then to Florence & later south. See if there's an option that you like where you can have less travel time for this quantity of days; otherwise, your trip will be more transportation time than fun adventures.

That was very helpful thanks!

Hi Jean, with our trip length I already took travel days into account. I'll provide a little more detail on the trip, I apologize that I didn't include that on my first post.
-10pm we arrive in Zurich and hopefully take a night train to our hotel.
Day 1 - Full day in Switzerland
Day 2 - Full day in Switzerland
Day 3 - Full day in Switzerland
Day 4 - Morning train to Florence and arrive at noon.
Day 5 - Full day in Florence
Day 6 - Full day in Florence
Day 7 - Train to Rome
Day 8 - Full day in Rome (just Vatican and Colosseum)
-Fly home the next morning

We can increase our stay if needed

With your planned activities at First it would make sense to stay in Grindelwald. If you want to see the Lauterbrunnen Valleynas well, you could take the train upmJungfraujoch from Grindelwald, but return down the other side of the mountain via Wengen to Lauterbrunnen, explore a bit, and return to Grindelwald by the Valley route. Or you could ride cablecar and gondola back to Grindelwald from Wengen, over the Männlichen ridge.

There is a mountain inn right at the mid-station stop on the First gondola that I have always found tempting, but we have not made our way there as yet. It would be a fun place to stay.

https://www.bort.swiss/en/alpinhotel-bort/

With a 10 pm arrival at Zurich younwon't be going to Grindelwald, as trains there do not run that late. You could get as far as Interlaken Öst, but the last reasonable train departs the airport at 22:43, and it is unlikely you would be off the plane and through immigration by then.

There is a later train, but younchange three times before getting to Interlaken, in Zurich, Bern, and Thun, finally getting to Interlaken around 7 am the next morning, after a sleepless night.

So it might be best to plan on spending that first night around Zurich.

You will find the train schedules at SBB.ch.

You can't get a night train that late at night (10 p.m.) to Grindelwald, Wengen, Mürren, or Lauterbrunnen--all places that are closer than Interlaken. The latest is 8:43 p.m. from the Zurich airport. (See Swiss train schedule at www.sbb.ch/en) So you'll have to stay somewhere else that night. You could get a late night train to Interlaken, but you wouldn't see anything on the way due to darkness, and there's no scenery in the city of Interlaken, anyway. Night trains do go to Bern or Luzern (Lucerne) and either one is about an hour away from the Zurich airport train station, and would give you a fresh, head-start in the morning to take a scenic train ride from there to Grindelwald for the rest of your stay in that area.

You said you can increase your number of days for this trip, if needed. There are two places you said you want to see in Switzerland: First (a cable car ride above Grindelwald), and "Top of Europe" (a train ride [from Grindelwald/Grund or Wengen, via Kleine Scheidegg] up to the Jungfraujoch). Those depend on views of the spectacular scenery, and views are weather dependent. I go in the summer and I find it best to double my time there to improve my chances of weather that's clear enough for good views. And there are plenty of other spectacular things to see from that area, especially if you're lucky enough to have more good weather days than bad.