Thank you everyone for your responses and advice. It was particularly enlightening to read raybo and steve0000's advice and Swiss cycling trip logs. That was exactly the feedback I was hoping to receive when I posted to this forum. Your experiences will definitely influence my trip planning. While we want to experience Switzerland via bike, I don't want it to be a Herculean grind either. I am blessed to have a can-do stoker, but have to keep her happy so she will agree to future trips (thus need to seriously consider steep grades and she has made it clear "no camping!") We may consider instead doing day trips from one central location instead of a point-to-point ride, or using one of the established cycling tour outfits in Switzerland.
Cost of travel in Europe is always a consideration, but we are also balancing the remaining years we have to make such trips. As our travel tandem packs into two standard-size suitcases as checked baggage, it doesn't appreciably increase our travel costs, just adds to the logistical challenges.
Thanks again. I enjoy reading your travel logs.