I can't see the UK applying to re-join, or the EU being prepared to spend much time considering the application, until both the two main political parties in the UK broadly support the idea.
At best, Labour will win the next election and spend the next four or five years trying to "make Brexit work," while adopting a more cooperative and conciliatory approach to the EU in trying to resolve particular issues that both sides want to see resolved in the interests of a more harmonious relationship.
Meanwhile, members of the Conservative Party, recovering from what will likely be a crushing defeat in 2024/25, will probably decide they lost because they were insufficiently right-wing and anti-EU, and choose someone like Suella Braverman or Kemi Badenoch. This won't work, and they'll experience a similarly disappointing result in 2028-9, at which point they'll see sense and try to move back to the centre ground.
Meanwhile, although Labour will have presided over marginal improvements to our relationship with the EU, it'll be clear to everyone that any real progress will depend on our having a much closer relationship with the Union.
At this point, quite possibly under a new leader themselves, Labour will be able to talk about discussing a new relationship with the EU. To my mind, it'll become clear sooner or later that the only sensible option -- and the most advantageous to the UK -- would be re-joining as a full member, though I think that it's going to be harder than people expect to persuade the public of the benefits of free movement and joining Schengen, even if the EU is prepared to accept some sort of a fudge about our adopting the Euro (Sweden, I think, have retained their currency without difficulty).
But by this time we're well into the late 2030s, and my crystal ball doesn't see that far ahead.