Place potatoes into a large pot and cover with salted water; bring to a boil. Reduce heat to medium-low and simmer until tender, about 20 minutes. Drain, cool, and cut into cubes. Place bacon in a large skillet and cook over medium-high heat, turning occasionally, until evenly browned, about 10 minutes. Drain bacon slices on paper towels; crumble. Preheat oven to 325 degrees F (160 degrees C). Lightly grease an 8-quart baking dish. Combine potatoes and bacon in a large bowl. Mix Cheddar cheese, cheese sauce, sour cream, mayonnaise, onions, chives, salt, and pepper in a bowl. Stir cheese mixture into potatoes; transfer to baking dish and cover with aluminum foil. Bake in preheated for 50 minutes; remove foil and continue baking until cheese is bubbly and lightly browned, about 10 minutes.