Try thinking outside the box
My original point was for a 3 man shuttle crew. Putting a Soyuz in the cargo bay is a great idea by DALeffler. They could release the Soyuz in a slightly lower orbit near by if needed and use it after the repair of Hubble. So the only technical question is can Hubble be repaired with two astronauts (one remains in the Shuttle)?
Of course there are political questions too.