Welcome, Gwenschled! Reading this, I don't see why it can't be frozen after baking.
I would reheat it before serving, to re-crisp the pastry.
I make quiche and freeze it all the time, and this is similar. Allow plenty of time to defrost it.
Also, if you're anywhere near a Trader Joe's, they now sell an all-butter frozen puff pastry.
Good luck!