You clearly don't understand a referendum, do you.
While this particular referendum on leaving Europe was not actually legally binding, I cannot see any government not implementing it, because it would simply crush any notion of the UK being a democratic country.
There is no way back. We have to leave. The only way that it could be avoided is by this government calling a general election before invoking article 50, and the election being won by a party explicitly campaigning on not leaving Europe.
I could see a centrist Labour offshoot campaigning in coalition with the Lib Dems. and possibly the Greens on this agenda, but I don't see that they would win a majority, although they could probably gain the largest share of the vote of all groups. But they would not have the clout to actually form a government able to carry out the policy.
It is unlikely that the Conservatives campaigning on such an agenda would win (it would show severe hypocrisy) and would split the party, so it would be as much political suicide for the current incumbent as calling the referendum on such a blunt question in the first place was for the former one.
But Teresa May has said that she won't do this, so it's moot.