Preheat the oven to 400°F. Lightly rub each potato with oil and prick several times with a fork. Place on a baking sheet and bake until tender, about 45-60 minutes. Remove from oven, let cool slightly, then chop into cubes (skin on or off, as preferred).
While potatoes are baking, heat a large pot over medium heat. Add the bacon pieces and cook until crispy. Remove and set bacon on a paper towel-lined plate to absorb excess grease. Leave the remaining grease in the pot.
Add the butter to the same pot and melt. Add the chopped onion and cook until soft and translucent, about 5 minutes. Add the minced garlic and cook for an additional minute.
Sprinkle the flour over the cooked onions and garlic, stirring to coat. Cook for about 2 minutes.
In a small bowl or measuring cup, combine water and Member's Mark™ Chicken Base.
Gradually add water/chicken base mixture, milk, and heavy cream to the pot, whisking constantly to prevent lumps. Bring to a simmer. Add the chopped baked potatoes to the pot. Bring back to a simmer, reduce heat to low, and let simmer for about 10 minutes.
Add Member's Mark™ Sea Salt and Member's Mark™ Fine Ground Black Pepper to taste. Stir in sour cream and half of the cooked bacon, reserving the rest for topping. Heat through until combined.
Ladle soup into individual bowls. Garnish with shredded cheddar cheese, chopped chives or green onions, extra sour cream, and reserved crispy bacon pieces.