Mix sour cream and onion soup mix together in a bowl; chill in refrigerator for flavors to blend, 2 hours to overnight.
Place potatoes into a large pot and cover with salted water; bring to a boil. Reduce heat to medium-low and simmer until tender, about 15 minutes. Drain and cool slightly. Slice each potato lengthwise and carefully scoop insides using a melon baller or small spoon, leaving a small border of filling; transfer potato filling to a bowl.
Mash or whip potato filling using an electric mixer, adding 1 to 2 tablespoons sour cream mixture at a time, until desired flavor is reached. About 2/3 the container sour cream will be used. Spoon potato-sour cream mixture into potato skins, forming a mound of filling; top with bacon. Refrigerate stuffed potatoes for filling to set, at least 30 minutes.