According to this a beer pitcher holds 3 3/4 US pints, which is a little over 3 Imperial pints. I don't think anyone swigging 9 pints in a session would be all that welcome in a UK folk club either.

If Conrad were really interested in music rather than getting pissed then he could cut down the amount he drinks and spend the same in the Wharf Rat as he would in other bars. If he doesn't like the real ale they serve other stuff. But I think we've established that the music isn't his priority.