Combine eggs and milk in a large bowl until well blended. Heat butter in a large skillet over medium heat. Add egg mixture, season with hot sauce, salt, and pepper, and scramble until set and cooked through, 3 to 5 minutes. Transfer to a large bowl. Heat the large skillet over medium-high heat. Cook and stir sausage in the hot skillet until browned and crumbly, 5 to 7 minutes. Transfer sausage to the bowl with cooked eggs, leaving grease in the skillet. Add potatoes to the greasy skillet and cook until soft, following package instructions, 15 to 20 minutes. Transfer to the bowl with the egg mixture and let cool, 15 to 20 minutes. Stir cooled potato mixture until combined. Top with Cheddar cheese and stir again. Scoop mixture into the center of each tortilla using a 5-tablespoon scoop or 2 large ice cream scoops. Fold tortillas and roll into burritos. Serve or roll burritos in paper towels, then in pieces of foil. Freeze. When ready to serve, remove foil and towel and microwave until heated through, about 2 minutes.