Stir together cold mashed potatoes, cheese and bacon. Scoop 48 tablespoons of potato mixture onto parchment- or wax paper-lined baking sheet. Refrigerate 15-20 minutes.
Meanwhile, place tortilla chips in bowl of food processor and pulse to fine crumbs, or place chips in large resealable bag and smash using a rolling pin. Pour crumbs into shallow bowl.
Beat eggs and pour into another shallow bowl.
Pour flour into shallow bowl; set aside.
Heat oil in fryer or Dutch oven to 350 F.
Remove mashed potato scoops from refrigerator and roll into balls. Roll each ball in flour, tapping off excess.
Once all potatoes are coated in flour, dip each into egg, allowing excess to drip off, then into the tortilla chips, making sure to coat evenly with crumbs. Set on clean baking sheet. Discard excess flour, egg and tortilla chips.
Fry small batches of poppers until golden brown, 30-40 seconds. Remove from fryer and place on paper towel to drain excess oil. Serve hot with sour cream, if desired. Poppers can be reheated in 350 F oven for 6-8 minutes.