It's interesting to me that, with a lot of replies, the best place to hold the next Celebration is, coincidentally, in very close proximity to wherever that particular poster is from.
Anywhere but Canada, is all I ask. 
True.
My suggestion for Minneapolis is actually based on the observation that it is one of the larger centers capable of handling large conventions. Indianapolis is not such a place, rather it is considered a medium-sized convention venue and the scope of CIII was really beyond its ability to handle the event, well before it ever started. Even the airport in Indianapolis is considerably smaller than suitable for an event of that size.
But suggesting Minneapolis was as much a joke as anything else, given my proximity and the disproportionate preponderance on Vikings around this place.
As for Canada, what a nightmare that would be
Between our stupid taxation and the rapidly changing border requirements (initiated, I might point out, by U.S. regulations) they couldn't select a worse location. They'd be better off holding it in Mexico than Canada, of that you'd have no argument from me.
As for "real" suggestions I'd think Minneapolis (really), Las Vegas or perhaps Denver would be suitable given the size of facilities and ease of travel. Many cities are too expensive for many people, somewhat the opposite of Indianapolis and these would include Boston, New York, Los Angeles, Chicago and San Francisco. Others probably have the perception of being 'riskier' from a personal safety standpoint - Detroit, Philadelphia, Atlanta, Oakland.
And no, I'm not pulling this stuff out of my backside, they are real considerations for a number of meetings that get organized on a U.S. national level. The meeting size is indeed considerably smaller than what CIII was or CIV would be, but the considerations are the same for the success of the meeting: will people feel safe and attend; will people be able to afford hotel accomodations; will people be able to (mostly) stay close to the venue; is public transportation satisfactory for the venue and if not, is there enough parking? All considerations for the meeting I'm reasonably sure.
Like you (not that I'd have a choice) I'd much rather travel to this event. I've no idea why anyone would want to stay home, you're bound to miss so much more by doing so. I know with meetings we've hosted you attend what you can, but the option of going home to see the family at days end holds some appeal, either out of desire or obligation and you miss out on so muc of the cameraderie of the event.
For me flight costs vary remarkably little, so long as I book in advance. Fort Lauderdale, San Diego and Bloomington, IL all cost the same for me, so it's not really a factor. I'll readily admit to bias towards Minneapolis though, that'd be cheaper than anything else and the flight time would be really short.
