I haven’t frozen this recipe but I have frozen small meatloaves to reheat before so I would think it would be similar.
If you want to freeze them before cooking them, just mix the mixture, roll them into balls and place them on a baking sheet. Pop the baking sheet and meatballs into freezer for about an hour to flash freeze them. Once they’re froze, you can put them all into a freezer safe bag and store them in the freezer until you’re ready to bake them. Of if you want to bake them first, follow the directions but make sure to use a disposable baking tray or one you don’t mind leavening in the freezer. Then just bake, cool, wrap and freeze. For my mini meatloaves I always bake them first and then wrap each one in foil and freeze it.