The negotiations are under way, worst-case scenario (and given the past this might well come true) is that nothing will be agreed on by the 22nd of March. In the 4-party negotiations from the 22nd-29th March there may be an agreement on some issues with regards to security. Then the gaps will be filled by the UN and we will have to vote for that plan.
What I think will happen at the end, although I would like to be proven wrong, is that the GC community will say a big NO to the plan. Listening to discussions on the radio in which people voice out their complains about the UN plan, this is the impression I get. I don't want to discuss why this is so, it's probably related to what GCs think a solution would be like. So what will happen next? Is there a hope for a "better solution"? The affirmative answer will be a tool for convincing GCs to vote "NO" with a hope of a better solution when in the EU.
Both sides will pay the price of a NO - and the price will be bigger than a YES.