So if we have BrexitRef2, why not BrexitRef3 or 4 or 5 etc etc just to make sure or just in case people have changed their minds? After all that's democracy in practice right? 
Ah no, that would be silly!
Especially if BrexitRef2 produced the 'right result'! 
It's a legitimate concern, but it's not silly at all. After all we've already had 2 BREXIT referenda. One in 1974, and the one in 2016. What arbitrary time limit between referenda on the same subject would you suggest? We nominally have General Elections every 5 years, but should a govt fall then in principle we could have one every few months. People can and do change their minds.
I don't like referenda one bit - we elect politicians to try and understand all the issues and take the important decisions. Asking the public a question that they do not and can not understand all the implications is daft. If you do, then IMV you should require a lot more than a simple majority to change the status quo - even more so if it's effectively a change to the 'constitution'.
This possibility just makes it worse.
If people do change their mind and more people vote remain then 'team leave' will insist on making it the best of 3.....or 5.....or 7.
If people didn't change their mind then we'd have had the same government in office for the past hundred years.
Yes I'd expect team leave to continue campaigning.
If people vote the same way as before then 'team leave' will win again proving there was no point to a second vote.
That's only true if the question is the same as before. If it's an explicit choice between Hard/WTO Brexit and Remain on the same terms as before then it's a different question, with options the public understand better now, and can be delivered by the Govt (assuming remain is an option). If team leave win a second time with such clear options then few would quibble.
I've read in various places that the Irish govt have already asked the ECJ for a ruling on if Art50 is revocable or not. Can't find anything listed in the ECJ schedule though. If the answer to that becomes important then the ECJ can expedite a decisions in 4 months apparently. End of November then.