You need five to six potatoes. Bake potatoes in their jackets in an oven set to 350 degrees for about an hour. Refrigerate potatoes for several hours, peel jackets and cut into 1/2 inch dice pieces.
Place peeled potatoes into a very large mixing bowl and add 1 cup diced red onion, 1 1/2 cups diced celery, 1/2 cup cooked bacon bits, 1/2 shredded Cheddar cheese and 1/2 cup shredded Monterey Jack cheese.
Mix ingredients with potatoes.
In a separate mixing bowl, mix: 1 cup sour cream, 3 cups ranch dressing, 1 tbsp course ground pepper, 2 tsp roasted garlic powder, 1 tsp celery salt and 1/4 cup chopped parsley.
Whip Step 2 ingredients together and fold into potato mixture in a very large bowl with a large rubber spatula. Cover and refrigerate for three to four hours. Enjoy!