What Earl said.
The maintenance meet (as well as just about every other major event we've tried so far) is definitely an annual thing now.
But Norm does have a good idea of doing a bit of it "on the side" during the other events as well. That was sorta the plan for Fall Colors Tour this year, we had orginally worked in plans for three days of events, with the tour being on Saturday and Friday evening and Sunday open for more informal gatherings, maintenance, etc. It just didn't turn out that anyone wanted to do that (most that came were fairly local) so we didn't, but we could have.
I can't speak for every location we might have an event, but definitely any time we have one in the Puget Sound area there is a chance of doing something like that. I know Earl is usually willing to host a pre or after gathering at his place and I have a big, dry garage as well.
Like Earl was saying a bit earlier in this thread, sometimes it is nice to gather at a garage in smaller groups outside of the big maintenance day so a few people can focus on more of their issues at the time they need to.
But of course for the minor things, and general knowledge, the big one in the spring is great fun!