The facts are that over the past 2 years there have been numerous GCA "outings" official and unofficial, open and secret. The most successful and enduring of these--the Kings Putter--was both unofficial and open and successful for these reasons, even though it was actually derided by some of the purists on this site for those facts.
The keys to these things is, as Nike used to say--JUST DO IT! Somebody, anybody, grab the possibility by the balls and organize a time and place. Build the event, and they will come, eventually.