Well, we can close the book on my first CKII GoT playthrough. Things had been going so well, too! The war to restore the Freys to Lords of the Crossing was successful, and my new lord was pleased with my help. My wife gave birth to twins, a boy and a girl, so I had an heir. But then, some other minor lord decided he wanted the Crossing and, well, his army was bigger. Even worse, the stupid Freys didn't fight back. So I was invaded and my territory was under siege. My family went into hiding, and I was captured. Now, how exactly the game ended I don't actually know ((#)&^)(&@%)& game won't let you see your messages after the "Game Over" screen pops up, so how this all went down is a little unclear), but at this point the game ended. I could see that I was now wearing black in my profile, so I was clearly stripped of my lands and titles and sent to the Nights Watch. I can only assume my heir (about a year old) was also stripped of these too, because he should have inherited. But alas, twas not to be.
Verdict is amazing game, fyi.