Is it best to freeze this recipe before or after baking it?

Whenever I've made extra meatloaf, I freeze it before baking. When you're ready to cook it, just take it straight from the freezer to the oven; no defrosting necessary.

One nice little trick: line the inside of the tin you normally bake meatloaf in with foil. Put the uncooked loaf in the foil, freeze until completely frozen, then remove the loaf with the foil. This way when you're ready to bake the loaf, it will fit perfectly inside your loaf pan.

I would freeze before baking. I tend not to freeze already cooked meat and have never done it myself so I cannot say how it would be.