He's not about to slip out of view, but the attention will turn quickly to Ardern, much of it in the form of congratulation, most in the form of pressure.
The scrutiny Ardern faced in that tumultuous campaign will only multiply in government. And the challenge is daunting: leading a coalition with a cantankerous, protectionist, populist New Zealand First Party; dependent, too, on the support of a Green Party whose MPs will inevitably, and quickly, find pragmatism and principles in tension.
If it seemed an ordeal to sew a new government together, that will be nothing to the effort required to keep its seams intact over three years.
If the elation of taking government is to last longer than the potato chip crisis of 2017, Ardern will need to move fast to push forward with the pledged action on child poverty, on the environment, on mental health, on the housing crisis and more.
On top of that, and with a slender majority in Parliament, the three-part government faces one hell of an opposition. Occupying 56 of 120 seats, National will make a formidable force.
Bill English has now failed to make government in two elections, 15 years apart. Despite that, he has led his party to the biggest share of votes, had a good "I got up again" campaign, and can make a strong case to remain leader - if he wants it.
There will no doubt be many, however, who will see this is as the moment to renew the leadership. Is it the time for Nikki Kaye - who has twice defeated Ardern in Auckland Central - to step up? Apart from anything else, the Ardern experience suggests that voters rather like a new face at the helm.
For the first time under MMP, the Government will be a party that did not collect the highest proportion of votes.
But that should not impugn its legitimacy - the parties together command a majority of those votes, and under our proportional system that delivers a mandate.
And don't forget that Muldoon led two governments that collected the second biggest percentage of votes, without any supporting parties.
In the weird vacuum that preceded yesterday's announcement, as political anoraks faced a crashing hangover after the intoxication of the campaign (with nary a trickle of a leak, attentions focused on confectionery taken into meetings, repairs to a parliamentary escalator, extended analysis of a cryptic biblical citation, of a novelty necktie, and the meaning of words including afternoon and breakfast), there was plenty of scrutiny of MMP.
But - and we wait to see the details of a coalition agreement - this is how it is supposed to work. Peters held neither National nor Labour to ransom. They were free to chuck it in any time they liked.
And as Peters was keen to point out last night, the few weeks it has taken to form a government is modest in a proportional electoral system. The other day, the Dutch arrived at a government after more than 200 days of negotiation.
Germany, which held its election the same weekend as New Zealands, seems pretty comfortable about assurances theyre likely to see a government in place by Christmas.
Why did New Zealand First tilt as it did? Of course, the negotiations will have been crucial, both in terms of policy concessions and ministerial roles.
But for New Zealand First's septuagenarian leader and deputy prime minister (again) in waiting, the prospect of joining, not for the first time, a government in his twilight, must have weighed heavy.
In his announcement last night at Parliament, Peters said that people had come to view capitalism itself as ugly, that in dealing with rival suitors of National and Labour they faced a choice between a modified status quo and change.
On balance, New Zealand First's manifesto made an easier merger with Labour's than it did with National's. Peters loves to seethe at polls, but it won't have escaped his notice that the most recent public poll suggested 65 per cent of those voting NZ First preferred they go with Labour, against 25 per cent who wanted a National-led government.
And the slogan - Had Enough? - that accompanied Winston Peters' serious stare on party billboards, was hardly equivocal.
Ardern now leads a government of change. She has made history. The history she won't want to make, however, is leading a one-term government.
There hasn't been such a thing in her lifetime. She and her supporters deserve to breathe in a bit of We Did This euphoria, and then give everything to deliver the change New Zealand voted for.
