Add a new rule, as a subsection of cults (making it 2.1.6), named Moving Headquarters, with the text:

As a weekly action, a cult leader may send an order to the Auspex requesting a move of the cult’s head quarters.  Such a request must include the name of the location to which the cult leader wishes to move the HQ. Such a request is successful if the cult leader has at least N Believers (including the leader) distributed evenly between the current location of the Headquarters and the location to which it is moving, where N is the cult’s Secretiveness score.  Otherwise, the request fails.

If the request succeeds, the Auspex notifies the leader and all that cult’s member’s of the change.  In addition, he makes a blog post exposing the fact that a Cult has moved location without revealing the identity of the Cult, the old location of the Cult’s headquarters, or the new headquarter locations.
If the request fails, the Auspex notifies the leader of such.