I like what you are doing with this story.
The way you describe how Harry manipulates his magic. How he acts with his relatives and now McGonagal to get his way. His outlook on life is in line with the way he was brought up. If he goes to Hogwarts he'll end up in either Slytherin or Ravenclaw I bet.
The other two ways I see this progressing, with Harry going to another school or staying where he is. He might well milk McGonagal for all he can learn and decide to go to Beaubatons.
Given how involved his selfstudy in magic is, I don't see him opt for the muggle school.
Well done.