You are correct - Mueller has nothing. However, ending the investigation without a collusion charge will vindicate Trump and serve as the final humiliation for the disgraced media/Democrats. Therefore, I predict that it will continue through 2020 or until Trump finally fires him.
Where in. the. hell. is Sessions?
(Tucked safely away by Rosenstein under the guise of interfering with the “investigation” if fired.)
Sessions will go down in history as the man most hated for doing nothing.