Yes, meatballs in tomato-maple sauce can be easily frozen. To do so, let them cool completely, then transfer into a freezer-safe container or bag, and freeze for up to 3 months. When ready to enjoy, they can be reheated to maintain their delicious taste and texture. For reheating, thaw the meatballs and sauce before warming them up. In the oven, heat at 350°F (175°C) covered with foil, for 25-30 minutes. Alternatively, use the microwave by covering the dish and reheating on high for 2-3 minutes, stirring halfway through. These methods ensure your meatballs remain juicy and flavorful, just like when they were first made.