Cook potatoes in boiling water to cover in a large saucepan 30 minutes or just until tender; drain. Cool to touch (about 15 minutes), and cut into 1-inch cubes.
While potatoes cool, combine sour cream and next 4 ingredients.
Cook bacon in microwave according to package directions to crisp. Cool and crumble.
Combine potato cubes, cheese, and green onions in a large bowl. Stir sour cream mixture into potato mixture, tossing gently to coat.
Sprinkle with bacon. Cover and chill until ready to serve.