Polls, schmolls. The devil’s in the details. Is the plebiscite binding? What’s the timetable? Even if the good guys win the referendum, the powerful interests behind EU will do anything to thwart the will of the people. The referendum is probably no more binding than a congressional resolution.
The referendum is not legally binding on the UK Parliament — necessary pieces of legislation would still need to go through Parliament to complete the withdrawal process, so who knows?
This site claims there would be a 2 year process of withdrawal:
http://www.bbc.com/news/uk-politics-32810887