Holiday apartments are the answer for a family for their Swiss vacation. We are taking our son’s family next summer and we will be a group of 6: 2 grandparents, 2 parents, and twin boys. I was looking at options in Mürren and Wengen yesterday. The apartments listed with the local TI tend to be full-week rentals, Saturday to Saturday. If that works for you, great. Otherwise you can also look on AirBnB, as many owners or agents list their apartments there as well, usually without the date restrictions, although a minimum stay of 3 to 5 nights is common.
I was surprised to see that our favorite apartment in Mürren, a comfortable and modern 3-bdr 2 bath flat with beautiful views, is already booked for the exact days we want, but I cannot change our dates so we will have to try something new.
As far as far as getting to these villages, there is some confusion above. Wengen is served by cogwheel train, not by gondola. It is same train that continues up to Kleine Scheidegg on the route to the Jungfrau. For Mürren, the usual route is a cablecar (not the same as a gondola) up to Grutschalp, and a train along the cliff edge into Mürren. There is an alternate route by bus to Stechelberg and the Schilthorn cablecar up to Mürren from there, but that is not as convenient with luggage.
Note that a cablecar and a gondola are very different. A cablecar ( Luftseilbahn in German) is a large, room-sized cabin suspended from a cable. Most hold 80 to 100 people, who ride standing up (and I am not happy when they are that packed with people). Generally there are two cars at opposite ends of the line, acting as counterbalance. They dock simultaneously at stations at either end of the line for loading and unloading, then move at the same time, passing each other at the midpoint. There is a driver in each car.
You can see and ride in a cablecar at North American ski resorts such as Whistler/Blackcomb, Snowbird, and Jackson Hole.
https://www.whistlerblackcomb.com/explore-the-resort/activities-and-events/summer-activities/peak-2-peak-360-experience/peak-2-peak-gondola.aspx
A gondola (Gondelbahn in German) consists of many smaller cabins strung in series on a cable, each holding 6-8 people who ride sitting down. The cabins move continuously, so you board and disembark while the cabin is moving through the boarding area. There are no Gondelbahn lifts carrying people in the Lauterbrunnen valley, but there are several at Grindelwald, the next valley over. The famous Männlichen ridge walk can be reached from Wengen by cablecar or from Grindelwald by Gondelbahn. You can see photos of both types on the Männlichen website:
https://www.maennlichen.ch/en/
Unfortunately the narrative has been careless in translation, as they describe the “Royal Ride” on the roof of the cablecar up from Wengen as taking place on top of the “gondola cabin”. But the English schedule gets it right, listing the lift from Grindelwald as a “gondola cableway” and the other, from Wengen, as an “aerial cableway”.
I see this translation confusion on other websites as well, such as this tourism website:
https://www.interlaken.ch/en/experiences/poi/first-gondola-cable-car
Compare the German, which says “Gondelbahn”: https://www.interlaken.ch/erlebnisse/poi/firstbahn
On the other hand, the official website for the Grindelwald First lift gets the English translation right:
https://www.jungfrau.ch/en-gb/grindelwaldfirst/
In each case, regardless what the English says, the German correctly makes the distinction between Luftseilbahn and Gondelbahn. So it is just careless translation.
Sorry to belabor the point, but this is a pet peeve of mine. . .