He may fire masses of people in the federal government he considers insufficiently loyal. Trump issued an executive order in October that could reclassify thousands of
civil service positions as “policy-making” positions subject to termination at-will. He set an effective date of January 19, but he can move that up at any time with another executive order. I’m sure it will be litigated if he attempts it but there’s no guarantee the courts would rule against it and these employees would be in limbo in the meantime. We shall see if he goes through with it
He will most likely expropriate as much taxpayer money as he possibly can to himself, his family and his companies. I expect he will relocate himself and the White House staff to Mar a Lago at exorbitant rates. All he has to do is tell the White House staff to go to Mar a Lago. The government already has contracts in place with Trump’s resorts for housing federal employees at inflated rates. Would he have access to all the White House infrastructure? No. Would he care? No.
I still say he may resign so Pence can Pardon him or pardon himself (if he can get away with it) and his family members of any and all federal crimes. This will have the effect of letting him vent his spleen as well as leaving the government crippled for Biden. And he will continue to do nothing about covid. Otherwise, I don’t think the rest of his squatting days will be nearly as cinematic as the last month has been.
It's also possible he’ll lick his wounds, engage in whatever spiteful tactics he can think of and on Jan 20th he will handcuff himself to the heaviest object he can find, swallow the key and tell the secret service agents, “You can’t move me, it’s against the constitution, I’ll sue you, you’re fired, where are the ballots? It’s all on Hunter’s laptop etc”