When Mrs Merkel finally takes office almost six months after the general election last September, Germany and the European Union will be trying to work out where the path of the new alliance of Christian Democrats and Social Democrats will lead.
Observers expect more of the same — a cautious, steady-as-she-goes, centrist course – but politicians from all sides acknowledge the need for a response to Mr Macron’s vision for the EU.
Mr Macron wants a more closely integrated eurozone with its own finance minister, budget and governance — a model that he argues would steel the single currency against the next crisis.
Months of coalition haggling led to the issue being put on the backburner and everyone now agrees Berlin needs to respond.
But the 177-page coalition pact entitled A New Impetus for Europe offers few details on EU strategy.
It calls for “improving the functioning of the EU, especially the EU parliament” but does not say how.
It says Germany will pay more into the EU budget but offers no hints about how much that will be.
Behind the scenes, officials say dialogue has been running hot over these and the other details of European reform.
But German reluctance to pay more in or take on more risk for its EU partners means the coalition is unable to present the public with a done deal.
A number of conservative MPs have already ruled out steps, such as a Europe-wide bank deposit insurance, that could leave Germany on the hook for other countries’ losses.
One MP from Merkel’s Christian Democratic Union said: “It’s going to be difficult to keep the group together on Europe because there are number of red lines.”
European Commissioner Günther Oettinger, a member of the CDU’s executive committee, said: “When it comes to the question of deposit insurance, I recommend to everyone that they don’t say no.”
If Mrs Merkel has to fight to push through a measure like deposit insurance it may be impossible to pursue Mr Macron’s more ambitious aims for eurozone integration.
Much will depend on how the German republic reacts to the proposals. If the Germans do move, it will have to happen soon, before Europe enters another election season next spring.
Mrs Merkel is also facing a battle at home where many votes fear the new government will be unable to deliver any ambitious reforms.
Analysts point out that by definition, the return of the “GroKo” — a German contraction of “grand coalition” — was going to be anything but radical.
Olaf Scholz, interim Social Democrat leader and future finance minister, said the coalition would work “step by step, day by day” and agreed the coalition was not a “marriage of love.”
But at a time of global political upheaval with the rise of populism across Europe and beyond, Germans want more from their politicians.
Recent polls found around half of German voters opposed the Grand Coalition as “too boring, too unimaginative and too conventional”.
Or as a popular line on German social media puts it: “Wake me up before you GroKo.”