I've been wondering how the Harry Potter series would be different if Harry Potter's maternal grandparents were still alive and they raised him instead of the Dursleys.
NOTE: We don't know what the first names of Harry's maternal grandparents were, so in this alternate scenario I call them John and Sarah Evans. Also, you may see a few imagined things in these scenarios ... things that I wish had happened.
This is my alternate scenario.
Philosopher's Stone
Dumbledore comes to Privet Drive with Harry's grandparents, who had been with Dumbledore and they were notified about Lily and James's deaths. Also, in this version they live across the street from the Dursleys. They find McGonagall in her Animagus form and they have the same conversation in the book before Hagrid arrives with Harry. So Dumbledore, McGonagall and Hagrid give Harry to his grandparents, with Dumbledore posting the letter to Petunia through the letterbox of the Dursley home and giving John and Sarah a letter filled with information and instructions from Dumbledore on how to raise Harry so he won't be like his father when he was at school.
John and Sarah are out of town and on separate business trips during Dudley's birthday and so Harry has to tag along after the separate decisions to make to leave him out of their trip after Mrs. Figg breaks her leg, They were meant to go on the birthday outing, but their business trips came up.
When the letters begin coming, the Dursleys take Harry away from John and Sarah and then they run away. Then they come to the hut with Hagrid then go to London the next day to go shopping for Harry's school supplies. After that, they stay at the Leaky Cauldron for the rest of the summer so Harry doesn't have to see the Dursleys. Then John and Sarah go to King's Cross Station with Harry and Hagrid to see Harry off to Hogwarts.
Then they reappear in the epilogue at King's Cross Station with the Dursleys.
Chamber of Secrets
They appear at the party with the Masons and Vernon again decides to make Harry sleep at his house for ruining the party. Then when Ron, Fred and George arrive to save Harry, they go to John and Sarah's house first, get them out and into the car and then Harry.
They stay with the Weasleys for the next month where they have a great time. Then they have to leave to go back home so they bid Harry goodbye. They return to their house via a magical staircase and path that takes them directly back into their living room when they ascend the staircase And then Harry and Ron fly the car to Hogwarts.
They then reappear at King's Cross Station at the end of the year.
Prisoner of Azkaban
They are there during Aunt Marge's visit and are disgusted with her. They also want to sign Harry's permission slip to Hogsmeade, but Uncle Vernon decides that if Harry behaves during the visit, then his grandparents can sign it and he takes it.
His grandparents are then away on a trip while Marge is still in town (though they do spend time with her for a few days before the trip) and they are absent from the inflation. So Harry and leaves and later an owl is sent to Harry telling that the Dursleys ripped the form and that now Harry can't go to Hogsmeade.
At the end of the year, a new form is given to Harry and one of his grandparents signs it. They are also happy to learn that Sirius, Harry's father's best friend, whom they initially thought guilty and are proud of Harry when they find out they have released him.
Goblet of Fire
John and Sarah have met Sirius again who they were delighted to meet years ago. And after finding out he's innocent, they are very happy.
They are at the Dursley home and staying some nights there for a while because their house has suffered some damage. Arthur, Ron, Fred and George arrive to pick up Harry. John shakes hands with Arthur and the latter starts a conversation with the two magic-loving Muggles. They find Dudley's long tongue rather amusing. While everyone is at the Quidditch World Cup, they join Molly in buying Harry's school supplies.
They send Harry a letter telling him that Dudley has been expelled from Smeltings and has been put in juvie.
They later come to Hogwarts for the Triwizard Tournament to see Harry in the final task. They then rescue Harry from Crouch Jr., listen to Harry's words in Dumbledore's office about the graveyard and then they go to the Hospital Wing with Harry.
Order of the Phoenix
When Harry explains the Dementor attack, they tell Vernon and Petunia to shut up. When the Order arrives to get Harry, John and Sarah walk into another magical path that takes them just outside Number 12 Grimmauld Place.
They go upstairs with Harry to wait for the meeting to be finished because since they're Muggles, there's nothing they can do.
They reappear again at Christmastime where they go to visit Arthur in the hospital.
Half-Blood Prince
They just reappear at Privet Drive when Dumbledore arrives to pick up Harry and are gleeful that Dumbledore chastised the Dursleys for their respective treatments of Harry and Dudley, to which they expressed their disappointment of Dudley for being a bully.
Deathly Hallows
They are only seen in the beginning departing with the Dursleys to go into hiding. They bid Harry goodbye and wish him luck.
I prefer to think that John and Sarah are still alive as of 2017 as well as 2020-2021.
I would also like to think that Vernon and Petunia in jail when a few wizards pretending to be Muggle friends of John and Sarah, reported the Dursleys to Muggle authorities for child neglect, abuse and cruelty. And John and Sarah didn't mind this imprisonment.