Self absorbed selfish Grandmother; How do you deal with someone this extreme?

Apologies for the vent! My Grandmother is 89yrs and is getting worse in her behaviour. She has narcissistic traits, an air of self entitlement and has my Dad running round after her like her servant. She lives an hour and a half drive away, refuses to move closer to family or go into a care home. She insulted us when we posed the question, saying “why would I want to live near family, when my friends are here”. They are not really her friends, she has them running round after her whenever she needs something and doesn’t see they are doing her a favour. Where she lives is the ends of the earth and remote and luckily there is the village pub opposite her house where people there will pop to her if she asks. She is rude, self absorbed and she never asks how anyone else is. She thrives off people complimenting her appearance and must ensure she has her hair and nails done, she shows no interest in the rest of us, and will often praise every other stranger except my Dad (her only son alive). My Dad’s brother passed due to Covid at Christmas in 2020, which she seems to have forgotten about, she never speaks of him. Every time she calls my Dad, there is always some ulterior motive, him being too nice and using the excuse of her being old, will never stand up to her. It’s created so much tension at home. One conversation about her pressing the wrong button on a remote control can last half an hour long. This was today’s episode, she switched her tv to radio mode and couldn’t turn it back, even though she has another tv in her kitchen, she doesn’t want to watch that one and wants to watch the one in the lounge. She expects my Dad to drop everything and come running whenever something minor happens, like if she has run out of prawns or ice cream. Her hoover broke down recently and she expected my Dad to sort it immediately, even though she doesn’t hoover herself and has my cousin do her housework, she lives in a small one level apartment, hardly much to hoover and she is almost blind anyway. She gives my Dad £300 to spend on a hoover but £50 for Christmas gift. Not that it is about the money but her principles are all wrong, instead of showing her appreciation for everything he does it is more important she has the hoover. I am growing to resent her more and more as time goes on and it makes me sick to see her subtle manipulation and control over my Dad who himself is now into his sixties and has his own health concerns. He recently had a hernia operation after waiting over a year due to Covid, she called him on the first day, asked him once how he was and then proceeded every other call to talk about herself and what food she was running low on and when would he be getting her shopping. She has an air of entitlement, what she wants she gets. For someone from her generation I am always surprised, considering all of my friends Grandmothers are nothing like her, don’t want want want and actually show an interest in their family. She thinks she is the only person in the pandemic that the rules don’t apply to. She often says “I’ve had my life” implying it doesn’t matter about anyone else who suffers.
She is emotionally and mentally draining, the few examples above are just a fraction of the picture.
Every other day is dominated by whatever has happened to her, what has broken, what she needs fixing. She refused even home help, for someone to just pop in and check on her. Does it get to the point where someone else has to keel over as long as she is kept happy? How do you deal with someone this extreme? She doesn’t even have dementia or similar, which I could probably just about tolerate, but this me me me attitude is getting to the point where I am going to suffer my own sanity. I don’t believe in using her age as an excuse because of so many other people I know that don’t act this way.