Weird that being rude somehow doesn't include a guest who has chosen to stay longer than arranged, possibly breaking covid regs and generally continuing lifelong crappy behaviour towards his kids.
No... tis the woman, the child in that relationship that is wrong, rude and needs to suck it up!
These were my immediate thoughts, too. Rudeness only seems unforgivable when it's females who are administering it. For the sometime-dad who absents himself from her life at will and then imposes his company for longer than agreed - over Christmas no less - apparently an outsize piece of CF'ery is all in the day's work 
Those with loving, non-dysfunctional family relationships don't seem to understand this kind of predicament. The place of adults is to protect and care for younger, vulnerable people. Children were not born to appease adult feelings: grandchildren are not props to provide penance for grandparents who know they have failed as parents.
My MiL is one of these. Before the DC came she troubled to contact my DH all of about twice a year. She forgot his tenth birthday. She used her children as pawns in her dysfunctional marriage, frequently doing flits to her mother's house in the middle of the night dragging her confused, upset children in her wake. Her own mother had to warn her that if she continued in this vein the protection services would likely intervene.
There's a long backstory as to why, but I no longer see her and DH fully facilitates the relationship between the DC and MiL. I've stepped back and play no part in this at all.
This isn't a case of a daughter throwing her poor, lonely, long-suffering daddy who's done everything for her and lovingly raised her to adulthood. She owes him nothing, not even the conventional obligations of a child to a parent.
OP: I suspect the only way you can get your father to leave is to ask him to do just that. Subtle hints are unlikely to hit their mark with these types, unfortunately. To soften it you could always hide behind the Covid regulations. You've already been more than generous with your time, but with some people give them an inch and they'll take the whole of the (ever-growing) radius of Tier 4.
Polite language and powerful non-defensive communication is your friend. Good luck. YA in no way BU.