Put the potatoes in a large saucepan with enough water to cover. Cook over medium-high heat until fork tender.
Melt butter in a skillet and saute the onions.
In a large pot or dutch oven over low heat, combine the soups, broth and milk, stirring until smooth.
Add the sauteed onions, potatoes, cheese and bacon bits. Stir constantly until the mixture is blended and cheese is melted, about five minutes.