I've been there a few times already, but always in a group of at least 4 cars. I can tell you that some of my friends keep their cars on 2WD mode most of the times. But I consider these guys very experienced as they only needed to use the 4WD mode when getting someone out of trouble. My old boss even had to drive back (in an Isuzu Trooper, mind you) from deep within the inland sea only on 2WD because the gear-box malfunctioned.
So, I stand with TB that it can be done but will not risk it myself.