I suspect that few people have changed their mind. Some who didn't vote last time, would vote in a second referendum; some who did vote, won't bother this time.
Crucially, over one and a half million young people will be eligible to vote and approximately the same number of people have died. I'm not in a position to predict how that would affect the result.
If there is a second referendum, I would like funding to be crystal clear with much tighter restrictions on advertising. I would have no objections to neutral, purely factual websites being set up and TV programmes with people answering questions and concerns rather than the rants which Question Time, etc have become. Hopefully, people have become more aware of the subliminal messages in spam and bots.
I would also like to see a 60% threshold before any important changes are made.