Put the potatoes on a baking sheet and rub them with the oil. Bake until soft, about 1 hour. Let cool enough so you can handle them.
Slice the butter into pats and add to a large bowl. Add the bacon and sour cream.
Cut each potato in half lengthwise and scrape out the insides into the bowl, being careful not to tear the skins. Leave a small rim of potato intact for support. Lay the hollowed-out skins on a baking sheet.