Meatballs in sauce can also be served in a slow cooker set on LOW.
If you don't have 2 rimmed baking sheets, you can use any shallow baking pans instead. Just make sure the meatballs are spread into a single layer in each pan.
How to Freeze Meatballs
Loosely pack cooled meatballs in freezer-weight resealable plastic bags. Lay bags flat in freezer so meatballs will freeze individually. Store in freezer up to 3 months. Thaw in refrigerator several hours or overnight before using as desired.