If the prize pool is gigantic indeed, even a dead site can be revived with new signups  , so it's just a matter of proper advertising.
Making an announcement here + starting new topic in games and rounds (which is allowed) should do the trick if you give a little notice in advance.
I remember participating in trivia on some other site years ago. It was fun, but obviously everyone was googling for answers, which took away a lot of joy from it.