I think if one more country votes to leave between now and then a renegotiation and some core constitutional changes become more likely.
The basic problem is that the Leave side lied about the benefits of leaving, but they were absolutely correct that the core of the EU has become a neoliberal financial dictatorship with rather thin democratic wrapping.
If bigger cracks start appearing in the structure the leadership is going to have a choice between accepting more real democracy, or having the whole thing come crashing down.
Currently there are no bigger cracks visible, but the economic foundations in most of the EU are very shaky - so who knows where we'll be a couple of years from now?