Considering spending additional night(s) at Lake Orta or other lakes

I've seen this question asked in the past on this forum and my answer was similar to others' answers. We took the Village Italy tour in 2014. There were 12 married couples in our tour group. Only one scheduled an extra night at Lake Orta at the end, and when I heard from them later, they regretted the decision. Orta san Giulio is lovely but it's small. There's not much to do and see. The nearly 24 hour stay that the tour gives you is nice time to relax and unwind at the end of the tour. But most if not all of your tourmates are going to leave after breakfast on the last day of the tour and it's going to leave you feeling lonely and at a loss for how to fill your time for the rest of your stay. I remember what everyone else in our group did after the tour. My husband and I headed to Varenna. We loved it! Originally this was going to be by train, with a couple of transfers needed, but a train strike on the last day of our tour complicated everyone's last-day plans. A lot of people were flying home from Milan's airport that day so our tour director helped coordinate shared cab rides to the airport. At the airport, we rented a car and drove to Varenna. Another couple rented a car there and drove to Tuscany. Another left the airport in Milan as they had booked a two night final stay in that city. Two couples who'd come on the trip together headed over to Stresa after Orta san Giulio, and after that, they were going to continue their vacation in Switzerland. One couple was flying from Milan to London to spend a few days there before going home. Everyone else flew home to the U.S. from Milan. Varenna is stunning. I loved this opportunity to experience another village and lake in Italy's lake district after Orta san Giulio. Why not, when we were so close? Lake Como was beautiful.

A day in Orta is enough.
I don’t know if your tour covers lake Maggiore, but that is where I would head. Stresa is very close to Orta and very convenient for the Borromeo islands. Stresa is also connected to Malpensa via shuttle bus, as well as train (Via Gallarate, from where you can catch a quick taxi ride to the airport).
However I recommend at least 3 nights for lake Maggiore. It’s a major lake (no pun intended, since Maggiore means Major). There is a lot to visit and one day is definitely not enough.

Thanks for the suggestions, we are going to spend a couple of nights in Varenna before finishing our trip in Milan.

Lake Orta is very near beautiful Lake Maggiore. Spend your extra time there. Orta is good for a day at best. We didn’t care for it and wished we had stayed on Lake Maggiore.

Orta San Giulio ( and its tiny island offshore) is the nicest of all the villages I visited in the lake region. The lake itself is not that much of a talking point. However, do as Roberto suggests if you have a few days without a car.