We each had one carryon-size luggage for our 10 day Norwegian cruise (and in all, an 18 day trip), which included every type of weather from hot sunny summer to cold, rainy and windy. I would say to bring something for each type of weather you will encounter, including a light rain jacket, but don't duplicate anything bulky. The rain jacket can keep you warm from wind. We did have free checked luggage (and we checked the carryon size suitcases) but we just didn't want to haul that much luggage all over Europe. I don't think I'll ever take a regular sized suitcase traveling again. If doing it again, I would have left behind my "dress shoes" I brought, intending to wear them for dinner.