The thing that would concern me most about a 'leave' vote is a potential Cameron resignation, along with all the 'remain' tory MPs, and an ascension of Boris Johnson et al to the throne.
No one wants Jeremy Hunt and the camaraderie in power, do you?
Either that, or there will be another general election soon, and if Corbyn is on the 'remain' side, he may not get a vast support, either.