Germany depends on the votes of Spain and Ireland at the EU for a lot of things that Germany finds important.
If a measure at the EU level has enough consensus and Germany vetoes it, they'll see other members be a lot more likelly to use veto power on things that mostly matter for Germany.
Since Germany are in the curious position of being the EU member that benefits the most from the Free Market (they're the biggest exporter and their biggest market by far is the rest of the EU) and the Euro (their currency now is a lot weaker and hence they're more competitive because it's a currency union with far weaker countries, than it was back in the deutsche mark times), they can't even threathen to leave the EU as that would a bit like threatenning almost everybody else with a good time whilst they shot themselves on both feet.
Still, the most likely outcome is going to be nothing at all getting done at EU level, either way, if only because that's always the most likely outcome.