I believe the regime has a week left, 10 days at most. And maybe even less.
He has no way of leaving Tripoli. All the roads are blocked. He can only leave with an international agreement and I think that door is closed.
I think it would be difficult for Gaddafi to give himself up. And he is not like Hitler who had the courage to kill himself... I don't think the evolution of the situation in Tripoli will allow him to survive.
If Gaddafi goes down, Bashar al-Assad will need to take a hard look in the mirror. There's plenty to see in this mirror.