We never considered visiting Lago di Como on our many trips to Italy, assuming it would be prohibitively expensive to hobnob on the same exclusive waterway as George Clooney, Sting, and Sir Richard Branson. Because we were traveling in August, cooling off in the shadow of the Alps before flying home from Milan—only an hour away from this fabled wishbone-shaped lake—sounded idyllic. Because we were traveling with our son, his Roman wife, twin 4-year-old daughters, a 6-year-old son, and Nonna (their Italian grandmother), we needed a minimum of three rooms. Hotel prices were steep, so I searched “lakeside villas” and found many stunning dwellings with equally stunning prices: over $10,000 a night! Eventually I found some affordable possibilities on Airbnb and VRBO. After eliminating some because the pictured antiques might not survive our boisterous grandchildren, I discovered Ca Livia—a pink palace that crowned the hillside above Varenna’s postcard-perfect harbor. While …