1) The stance of the "Frugal Four" against the grant plan will be difficult to sustain - especially on their own, and especially without Germany's support. In all likelihood, the other members of the EU will rally around two of its leaders, France and Germany. The Frugal Four may try to negotiate, but in the end, it is likely that pressure to move ahead with a plan will force them to capitulate.
2) National leaders know how important it is to cooperate. They also know the critical need for a swift solution. Even if they have conflicts, they are on a timeline for negotiations. They will have to agree on a plan at one point or another - whether it looks like the current plan or not.