What is needed is something like WeWork for large office gatherings. Something between a WeWork and a hotel conference center. The former is not really made for big meetings. The latter is either very expensive, too large or too small. You need a space for 10-200 people to meet and collaborate... not a conference center.
and big conference centers are often highly booked and expensive; random hotels are often very cheap and easy to pull together with a couple of weeks notice. quality varies, but shop around.
source: wrangled a few impromptu "conferences" at a local hotel near data centers.
