Once you reach Vice Admiral you have access to all the patrol missions in Tau Dewa sector block and can visit New Romulus.
The new episodes are all ground based while the patrols are all space.
The episode progression works a little different than what you know.
You have to unlock them through the Romulan Reputation. When you reach a new Reputation tier you get the next episode, so you will have to to a bit of grinding stuff in between.