My Idea MLP X HP Crossover Fic

I have a Fanfic idea for Harry in Harry Potter being adopted by Twilight. Starting from Season 5, Starlight instead of time traveling, used an interdimensional magic and sent Twilight and Spike to London in 1981. The two were helped by Lily Evans, Harry's mother, when they were stuck in the human world. Then saved Harry from that fateful night and brought him to Equestria when Harry was 6 years old.

The problem is I'm stuck for an idea and I've only read part 1 of Harry Potter/I've seen all the Movies. I just wanted to ask what do you guys think, is the idea okay?