I don't particularly think we should have another referendum about it right now. It caused enough toxicity last time. But I do think Remain would win. A lot of people voted Leave because of the lying bus or other nonsense about the "sunlit uplands". Now they've seen the reality I'm not sure they'd be duped again.
I never understood the nonsense though that a one of snapshot of public opinion - which as that graph shows, changes over time - is a good basis for a policy which has consequences across generations, especially when the result was so close. I even heard people say that a second referendum would be "undemocratic"
. How the piss is a vote undemocratic? The argument was "you can't keep doing votes tell you get the answer you like", but why can't you have votes if there's indication that public mood has shifted? That's why we have regular general elections, so we can kick the government out if the mood turns against them. We don't vote in a government and then that's it for the next few decades because another vote would be "undemocratic".