Catalonian leaders are indeed approaching a dead end, and they do while a steamroller is coming from the other side, and this is the judiciary system. Right now most of the politicians are deep in red ink, in borrowed time.

They have asked multiple times to dialogue with Spain and negotiate a satisfactory outcome for all. But the steamroller doesn't stop. And who is on the driving seat of the judiary system/steamroller? Yes, the PP, the spanish nationalists, who have appointed the judiciary and are ready to bend it to their interest. Spain has one of the least independent judiciary systems in Europe.

And catalan politicians are in a dead end, because while there may be a majority for independence, nobody else is going to defend the legitimacy of a declaration of independence, and the more they resist, the more the steamroller accelerates and the darker the street.

What I see as the likely outcome is that catalan leaders will be jailed and only after PP loses majority/power, which is very likely in the next cycle, the catalan politicians will be pardoned.