PREHEAT oven to 400°F. Mix chicken, RedHot Sauce and 2 tablespoons of the butter; set aside.
SCOOP out inside of potatoes leaving a thin shell. Mash potatoes and stir in sour cream and remaining 2 tablespoons butter until smooth. Stir in chicken mixture, Cheddar cheese and blue cheese. Spoon mixture into shells.
BAKE 20 minutes or until heated through. Garnish with chopped chives, if desired.