We knew which hotel would hold the conference more than 2 years ahead of the Seattle event. That was part of the vetting process. The AHA comes in and they do walk-throughs of the proposed space with the local committee as a prerequisite to even accepting the bid to host the event. Part of the vetting process includes capacity, transportation, location with respect to supporting breweries, etc, local law considerations, etc.
The process is very involved and it really does take a couple of years to prepare.
Steve