In a large pot, bring potatoes and cold water to a boil.
Continue to boil until potatoes are fork-tender, about 20-25 minutes.
Drain potatoes, and return to warm pot. Let potatoes cool to room temperature in pot.
While the potatoes are cooling, whisk buttermilk, mayonnaise, yogurt, seasoning mix, and honey mustard in a large bowl.
Chop cooled potatoes into 1-inch pieces.
Toss potatoes and celery with ranch dressing.
Sprinkle with bacon and cheese, and season with salt and pepper.
Serve immediately, or refrigerate until ready to serve.