Generally, the status quo has the upper hand in referenda. However, in the wake of the global financial crisis and subsequent recession, the anti-incumbency trend might not just be contained to first-order elections, with voters punishing governing parties of all stripes for letting economic misery occur on their watches. It could be that this trend extends to the far more fixed and aggregate level. For example, in the Scottish Referendum, Better Together warned against Labour voters acting on this anti-incumbency impulse to end Tory rule permanently, as opposed to just temporarily at Westminster General Elections.
However, for a voter it is perfectly rational: if given the chance to either a) end something unpleasant for at least five years, with the possibility of it returning or b) end it permanently, any Rational-Choice model would dictate the latter. Many in the Scottish media laughed at a recent intervention by the UKIP Leader that he could persuade Scots to vote Leave. There have also been comparisons between the ‘Yes’ movement in Scotland in 2014 and UKIP and the wider Brexit campaign.
The English voter who was told to not vote for UKIP in May if they really wanted a referendum, and instead, vote Conservative, now has that chance to vote in that referendum.