Place cheeses and flour in gallon-size zip-top bag. Close bag. Shake until cheese is covered with flour; set aside.
In large Dutch oven over medium heat, cook bacon until crisp, stirring occasionally. Transfer to paper towel-lined plate; set aside.
Pour off all but 2-3 tablespoons bacon drippings. Return Dutch oven to medium heat. Add carrots, onion and garlic. Cook until onions are translucent and carrots are softened, 3-4 minutes. Add chicken broth, black pepper, red pepper flakes, thyme and parsley. Stir in potato salad. Continue cooking over medium heat 5 minutes, or until potatoes are heated through, stirring occasionally.
Reduce heat to low. Slowly stir in cream and milk. Cook 5-8 minutes until blended and heated through, stirring frequently. Slowly add cheeses, stirring until melted.
Top with bacon. Garnish with parsley or chives, if desired.