I suspect that McConnell will drag out possible Trump impeachment support as bargaining chip/leverage during Biden's first 100 days. The Dems have already hinted that they'd like to postpone impeachment hearings until after Biden has had chance to get his initiatives under way. The nice thing is that, should the GOP throw Donald fully under the bus to get a few things that they'll be wanting out of negotiations, the by then freshly restored Justice Dept will direct themselves to fully pick over his carcass, all without any prompting from the White House; for this is how the executive, legislative, and judicial branches of the US government are meant to operate, at least so far as when they haven't been compromised.
What I've always found most telling of Trump's stupidity is that he so easily allowed his ego to direct himself into politics, a world where his entire lifetime of misdeeds was bound to be laid bare, eventually. It was the first thing that crossed my mind on that day back in 2016 when he and his trophy rode down the golden escalator at the shorter than advertised Trump Tower. What an idiotic maneuver for someone so obsessed with optics! But, more so than that, what an idiotic career move for someone so dirty! I've known a few malignant narcissists in my lifetime, none were quite so dumb as to draw such scrutiny.
Of course, the only thing we know for certain at this point is that this will be DJT's finest hour on television, the ratings are sure to be huge.