>> We hope to spend a day in the Bernese Oberland midweek. The current forecast is snow Tuesday, Wednesday and Thiursday, getting progressively colder. We are a couple in our late 60's, mobile and healthy who enjoy walking but not committed hikers.
If you come from somewhere where you don't experience snow in winter, walking around the villages of the Jungfrau Region could be a fun and charming experience, as long as you are suitably dressed.
I have been in Mürren in such conditions, and while fog prevented any views of the mountains, the village atmosphere was wonderful in my opinion, and I enjoyed the experience immensely. I have attached some photos.
>> With the snow, I am assuming that going all the way up to Jugenfraujoch may not be enjoyable, as there won't be much visibility. What alternatives would you recommend?
Going up to the Jungfraujoch in snowy weather is still quite an experience if you are not used to that. However, it is hard to justify the expense. You could just go as far as Kleine Scheidegg. If the fog is quite dense, then it wouldn't be worth it, but if the fog still permits some views, and it is a bit on the wild side, with snow blowing about, it can be quite a thrill.
>> Should we plan to visit a village or 2 and if so which wouod you recommend?
I would recommend Wengen and/or Mürren. You may not get any views, but the villages are so charming and look beautiful under snow. Lauterbrunnen is less charming when the views are obscured by fog.
>> Or should we plan on visiting the Bernese Oberland some other trip?
Yes, come back some time in early autumn, for a completely different experience. But if this will be your only winter experience in the Berner Oberland, I would say go for it! You can still have a wonderful experience. However, if you come from somewhere where you get snow in the winter, such an experience may not have the same charm for you!