This exactly. My kids were the exact age of yours when we took the Norway cruise. It was perfect for our family. We loved that the ship docked in picturesque villages and towns. We could walk off the ship and stroll into town. We had private and Disney excursions, like Kayaking, Private bus tours, high speed zodiac tours, beautiful hikes. We are active and loved the daily ports. After we were returned to the ship, my husband would sometimes go for a run on his own, in the hills. He would ask the locals where to go. My only regret was not booking the Baltic Cruise which was right after ours. We thought we would be tired with all the adventures, but the ship was so relaxing that we could have gone easily for another week. It seemed pricey at the time, but since we were already over there, we wouldn't have to fly out there again! And we weren't jet lagged any more.
I booked a Med cruise but canceled and might reschedule for a later year. I have heard that the ports are farther away from the towns, and many require a bus or shuttle ride. The long bus rides are probably too much for my kids. For us, we may decide to travel at a slower pace on our own in the Med (several days in each town) rather than on a cruise.
