In microwave heat milk and butter until butter melts, about 20 seconds. In large mixing bowl mash potatoes with milk and butter. Stir in Buffalo sauce, 1/2 of the bacon and 1/2 of the green onions. Divide mashed potato mixture among potato shells. Sprinkle tops with the shredded cheese. Bake until cheese is melted and potato mixture is hot through, about 5 minutes. Sprinkle tops with remaining cheese and green onions. Serve with Gorgonzola Dressing.