Boil potatoes and onion until they are firm but starting to become of mashing consistency. Add butter. Salt and pepper to taste.
Stir in the milk, sour cream and buttermilk in that order, stirring between each addition. Add green onions and bacon. Add garlic
powder to taste.
To Freeze: Freeze in freezer safe container.
To Reheat: Heat in microwave until hot and thick, stirring every minute or so.