While this recipe is best when made fresh, leftover biscuits can absolutely be frozen. To reheat, place frozen biscuits on a parchment-lined baking sheet, cover them with foil to prevent over-browning, and bake at 350°F (180°C) for 10 to 15 minutes. Gravy can also be frozen after preparation, but it tastes much better when it's made fresh. To make things go more quickly on a busy morning, pre-cook your ground sausage days before and freeze it, then simply thaw and add it to your fresh gravy on the day you're planning on serving.