Dates? Saturdays in January are: 6th, 13th, 20th, 27th. 6th might be a bit optimistic, funds-wise, if your wallets are all taking the seasonal battering mine's looking forward to.
I'd also like to take this opportunity to suggest that no true londonpubcrawler should have any intention of giving up booze in the new year, as some lily-livered resolution types are wont to do. A bad business. *shakes head in dismay*