Since the consequences of the vote
are so enormous for our economy and society, it seems completely reasonable to me to do this in the same way that divorces happen: i.e. decree nisi for the initial recognition of relationship breakdown/separation, and decree absolut for the final irrevocable step.
So, let the government of the day decide when article 50 is to be signed (nothing actually starts changing before then, but obviously some ground-work and prep happens), and then have another referendum a week/month before just to make sure that it's really what is wanted.
Plenty of fuckwits around who now regret the way they voted, so let's at least ensure for something as momentous as this that voting preferences genuinely reflect thought and sentiments.