We plan to visit the Berner Oberland either the first or second week in October. It will be our first time in Switzerland. What can we expect for weather (temperatures) and will we be able to hike? Will anything be closed then (restaurants, hotels, trails, etc.)? Finally, is there an advantage to staying in the Grindelwald valley area versus Lauterbrunnen or Gimmelwald valley area? Thank you.
You will certainly be able to hike in early October. Most hotels and restaurants will still be open. Normally, it's a wonderful time in the mountains. But the weather can really be anything in any season, so dress in layers so you can easily adapt to the temperature/wind of the day or even the hour. More hiking related tips can be found on myswissalps.com/hiking.
Grindelwald, Lauterbrunnen and Gimmelwald are all in the small Jungfrau region. It's a matter of what you like best. Grindelwald is the largest town, the other two are really small. Grindelwald and Lauterbrunnen are both well connected to the rest of the region. Gimmelwald is pretty isolated and only to be reached by cable car.
Yes, those towns can be reached all year round, no problem. Most of the smaller lifts will also be running early October.