1 day — Day trip from Milan
Train to Varenna (1hr), ferry to Bellagio, walk the gardens, ferry to Menaggio, train home. Rushed but gives you a taste. Better than not going at all.
2 nights — Ideal
Day 1: explore your base village + ferry to Bellagio. Day 2: Villa Carlotta gardens + boat to other villages + sunset from your lakeside hotel. Two nights lets you settle in.
3 nights — Luxurious
Add: a hike in the hills above the lake, a visit to Villa del Balbianello (Star Wars, James Bond), a cooking class, or simply a day of swimming and reading by the lake.
4+ nights — The full lake
Add: Como town, Lecco (Manzoni's city), the Greenway del Lago walk, a day trip to Swiss Lugano (30 min from Menaggio). Four nights means you can try a different restaurant every evening.
Our recommendation: 2-3 nights
Stay in Varenna for the best value and atmosphere. Buy a mid-lake ferry pass for unlimited hopping between Varenna, Bellagio, Menaggio, and Tremezzo.