They take such things seriously on the other side of the pond!
http://www.crosswordtournament.com/info/brochure.htm
(Scroll down to 'Schedule').
Anax's idea sounds like a sound one to me (even though I'm rubbish at cryptic crosswords). Putting his own name behind it (which is well known to, and frequently cursed by, those who try to solve his clues) would give it an element of credibility. His contacts with several of the country's 'heavyweight' newspapers should enable the event to achieve some free publicity (as would a well-written press release to journals such as The Oldie, for example).
Perhaps (other than the possibility of incorporating the Times Crossword Championship into the event) there could also be the opportunity for a bit more competitiveness included. e.g. a pub-style non-cryptic quiz and perhaps a cryptic one too? Getting people to join up into teams (if they've not already come as part of a group) would help to increase the 'social' aspect of the event.