There is another side to the debate of course, and that is the effect of Brexit on the remaining 26 EU nations. Greece were unhappy at the way they were treated by the Central Bank, and In the first referendum held in Ireland, the vote was against the Lisbon Treaty. Other EU nations (given a referendum) made it clear that not all were in favour. So a Brexit would certainly shake up the EU although the long term impact is difficult to determine. In on case, it could accelerate the break up of the EU, or at least accelerate the reform, and perhaps put a break on the political integration.
That would have little immediate effect on the UK in the short term, but longer term may be beneficial to all the EU nations.