We may get the chance to vote again (in the dim and distant future) if we remain now.
I think the EU is going to have to change one way or the other as there are murmurings in some EU countries about the 'noses to the trough', governments are changing, new countries are joining and that brings new ideas to the fore. If that happens there's scope for another referendum (similar argument the SNP has about another Scottish referendum) because there's changes going on which may not suit us or any other single country in the EU. You may well find other EU countries may have their own referendum in the future and that could spark us to look again.
But it will be a long time coming if it's a referendum of the type we are currently having, rather than a vote on a treaty or something.
However, if you think you can vote Leave and ask to go back at some point I'd say it may be possible (very, very unlikely but nothing is ever impossible) BUT, the UK will be starting again. And that means potentially accepting the Euro and open borders (two things Leave have been saying are totally unacceptable).
Nineteen countries are in the Euro zone at the moment, out of twenty eight. More countries will join, eventually. Again possibly using the Euro. We'd have a bigger, and very different, EU to negotiate re-entry with.
Twenty six of the twenty eight current EU countries are in the Schengen zone. If we go, there are twenty six of the twenty seven in the zone...Any new ones joining will be asked to join Schengen.
Does anyone seriously think the UK would be welcomed back on the same terms as it left - not forgetting that (probably) at least 10 years (two years for the legal 'divorce' from the EU and another 6-8 years getting negotiations for trade etc in place) would have passed before the UK decide the EU may now work for it.
In those years the EU would have got used to the UK not being around the table, would have new countries on board who would have right of veto etc, would be generally pissed off with the UK anyway and, if we wanted to go back, we'd probably be failing or struggling because, if we were doing well outside, why would we re-enter? And failing or struggling means desperation and acceptance of any lifeline thrown. Anyone thinking we can 'change our minds and ask to rejoin' is being naïve to be honest.
If you think of it like a divorce, would you let your ex back into your life after ten years and accept them wanting to have the marriage exactly the same as it was when they walked out? Of course not, you'd be used to being without them, so you'd be bound to say 'only on my terms'.
BTW - just for the record - I am a "want to leave but have some doubts about the lack of figures" voter. So no vested interest in saying any of the above.