He would prefer the court to hand down a decision. If the court stops the proceedings, he would be more than happy to wash his hands of this mess.
But if not and the Liberals are still in power, he will get involved and stop the extradition process...
If Joe Biden is in the White House by then, this would happen very quickly. Because both the Republicans and the Democrats want to show the public they are tough on China, Joe Biden will NOT be willing to pay the political price for dropping the extradition charges against Meng. That would necessitate Justin to bite the bullet and stop the process himself. Of course, the US government will express 'regret' over Justin's actions but would the US government headed by Joe Biden sanction Canada? NOT a f_cking chance and it would happen very quickly after the court decision in May 2021.
However if Trump is still in power, it would be much trickier. Justin would try to secure a lot of support in both branches of US congress and the support of Governors (as the US's vital economic partner) before he would intervene. That could take some time but I believe he still would stop the proceedings eventually - maybe by the end of 2021 or early 2022.