I played some Party poker , peaked about $512 ahead, quit at +$77 ahead , after a night of Budweiser, you never know the your peak, but I recogized my valley. Quit ahead, the game will be there there next day !
I'd say, if you are up a large amount (I play omaha h/l) you should leave the table and go to another with the original amount you started with. Too many times I've been up a couple of bills and due to "loose all ins" I'll lose large amounts with boss low hand and possible high hand by slpitting pots. A little different in Hold 'em I think, but not much.
Shit I set my alarm to wake up and play all the drunks. Just not a good thing to do if you want to try an make money. Don't drink and drive = don't drink and gamble.