Speaking as one who lives in Kansas City, uh... wow, that's a long drive!

Not unbearable, but I doubt I would make the trip. One day to get there, the weekend itself and one day to get home = more vacation time than I want to spend! But that's just me.
I love the idea of a BIG get together of Smarts, but I wonder if it might not be worth considering to have (pick whichever word you like) several / a bunch / tons of smaller meets on the same day. I'd wager we can get at least 50 Smarts together in KC (being conservative), and there are quite a few active clubs that may be able to do likewise, so... perhaps cumulatively we could achieve a BIG meet.
I know, it ain't the same, but if we're already agreed (are we?) that a national event is out of our present reach, why not aim for that goal NEXT year, when there are twice as many of us. Let THIS year's goal be the successful establishment of multiple Regional Smart meets, thereby laying the groundwork for a "joining" next time.
Don't know if it will actually work that way (my idea may simply lead to more regional meets next year), but the practice would sure be good!
Don't construe anything I've said to be "I don't like your idea!" I DO! I just want it to be closer!