Potato Salad Dressing

From great-Grandma S., this is from her friend Hattie.

1 C. Miracle Whip (do not use mayo!)
1 C. whipped cream
1/2 C. vinegar
1/2 C. sugar
2 T. mustard
1 tsp. salt

Mix well, add to cooked, cubed potatoes and let sit overnight.