What doesn’t kill you makes you stronger, as the saying goes. And looking at Theresa May – still standing, somehow, against all the odds – some have been tempted to apply it to her. After all, Boris Johnson’s resignation has, if nothing else, relieved her of the single most destabilising influence in her government and a source of national embarrassment overseas.

His replacement, Jeremy Hunt, is a remain voter whose claim to be a convert to Brexit is regarded with deep scepticism, and who is less likely to give casual offence to EU allies. William Hague is right to argue that Monday’s psychodrama separated the realists – those prepared to accept that the Brexit they want doesn’t actually exist – from romantics such as David Davis, who are willing to follow their dream all the way out of the door.

What’s left is a more pragmatic, flexible, less ideological cabinet with a more sober understanding of just how few options it has. (Dominic Raab, the new Brexit secretary, may prove to be the exception to this rule, but he may find himself further out of the negotiating loop than Davis was: Olly Robbins, the civil servant who is leading talks with Brussels, looks more dominant than before.)

But the truth is, what doesn’t kill you sometimes just comes back to get you slightly later. And in the meantime, as John Major found out when he won his back-me-or-sack-me showdown with his own MPs, only to be sacked by the electorate two years later, it doesn’t half batter the immune system.

The chances of a relatively sane Brexit still look healthier than they did a week ago, despite some formidable hurdles still to be cleared. Theresa May’s own long-term prognosis looks more questionable, however, whether or not there are more resignations to come.

Jeremy Corbyn survived a mass exodus from his frontbench because Labour members were right behind him even if the parliamentary party wasn’t, and that created a roadblock to getting rid of him. May has the opposite problem. Tory MPs may still be too frightened of triggering a general election to move against her but there are deeply ominous rumbles coming from grassroots members, who are more viscerally opposed to compromise on Europe than their departed cabinet champions.

The Tory rightwinger Peter Bone was mocked in the Commons when he said his local members were so furious about what they see as a Brexit betrayal that they are refusing to come out and campaign. But a mutinous go-slow by Tory activists, just as Labour is overrun with eager helpers, could have profound consequences in marginal seats. Since this is the season of the Conservative association summer barbecue, many Tory MPs will return home this weekend to an earful that may yet colour the mood.

And even if rebels don’t currently have the numbers to mount a leadership challenge, May still faces the prospect of death by a thousand cuts to the forthcoming Brexit white paper fleshing out the Chequers deal, and this would ultimately lead her back to the same place. Jacob Rees-Mogg and his Brexit vigilante army are already threatening to pick the plan apart in parliament, while Labour has strong reservations about its reliance on some mystical, yet-to-be-devised “smart technology” allowing Britain to collect customs tariffs at borders on the EU’s behalf.

Given the fact that EU negotiators are equally sceptical, it’s likely that further pragmatic compromises will be necessary. And that may be more reality than the Conservative party can bear.

There is a theory that all Theresa May now really wants is a deal – that any lofty personal or political ambitions are long gone, leaving what she sees as one last, patriotic duty to secure a Brexit that doesn’t burn the house down before yielding to whichever successor seems least likely to destroy the Conservative party. That fits with a reshuffle that, as well as promoting pragmatists, pushes into the spotlight some of those who fancy their chances in a few years’ time (Raab; the new health secretary, Matt Hancock; and Hunt).

But whether or not it’s what she wants, it is probably the best she can hope for. The patient is out of intensive care and rallying better than anyone expected. But it feels like a reprieve, not a whole new lease of life. Like anyone painfully reminded of their own mortality, she should make the most of whatever time she has left.

• Gaby Hinsliff is a Guardian columnist