I think they can always make a new Halloween story line. They should stick with his family line. Michael has two nephews one from his niece Jamie his sister daughter the boy Tommy Doyle finds him and runs away
Michael other nephew from his sister Laurie is hidden with his mother at a private school and they both escape
Then later his sister is just shown with her new kids her daughters and they finally kill Michael but nothing is ever mentioned of his nephews what became of them?