How long of a notice would Defcon have to reschedule? Especially since they probably have the hotel booked and everything else? Also they would have to inform all speakers that it would be held in Mexico / Canada and some people might not want to come so it really just hurts the Conference in general. But regardless we still have to wait and see if Visa letters start getting rejected.
8-12 months, most likely. I guess the most plausible situation would be a split con, with most of it still in Las Vegas, but live VTC stream to a parallel con elsewhere.
Black Hat would not move; Defcon and Blackhat hate each other now, but it's still a big draw (your work usually will let you expense Blackhat, and Defcon is on the weekend after)
