Cut potatoes in half, and scoop out insides into large bowl. Add softened butter; mash with potato masher until most of the lumps are gone. Stir in sour cream, half-and-half, salt and pepper. Reserve 1 cup of the cheese, 3 tablespoons of the crumbled bacon and 1/4 cup of the sliced green onions for topping. Stir remaining cheese, bacon and green onions into potatoes.