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 and transfer potatoes to a large bowl.
Mash sour cream, cream cheese, salt, white pepper, and garlic into the potatoes with a potato masher to your desired consistency; transfer to a baking dish, cover with plastic wrap and refrigerate 8 hours to overnight.
Preheat oven to 350 degrees F (175 degrees C).
Drizzle melted butter and sprinkle paprika evenly over the top of the potatoes.
Bake in preheated oven until hot in the center, about 30 minutes. Garnish with chives.
