It’s not an orthodox problem, it’s a Roman problem. The ancient church, in emulating the governing structure of Rome, confused it for the shape of the Body of Christ itself.

Matthew 18:20: For where two or three are gathered together in my name, there am I in the midst of them.

This is all we need for true orthodoxy to survive; two people who can meet and share the faith. As long as we have this, historic Christian orthodoxy will survive.