In a nutshell: I have a preschooler who now loves Harry Potter. At what ages did you let your kids read/see the third installment and up?

Last weekend, I showed my 5yo Harry Potter and the Sorcerer's Stone so he'd have another topic of conversation during a play date. If the circumstances hadn't been what they were--first time meeting another gifted kid his age--I probably would have held off introducing him to Harry Potter for a few years, and I would have started him with the books instead.

Well. To say that he took to his first taste of Harry Potter is an understatement. The following day he asked to start having the book read to him at bedtime. Then he asked if he could hear two chapters instead of one the night after that.

My question: Now what do I do? I can read him the second book, but I can't see how the third would be appropriate for a five-year-old, even one who knows that death exists, and can read a few grades ahead no problem, and is really eager for more.

Has anyone been in this position? I'm assuming we'll have to rotate books and movies one and two for a while, maybe with the Quidditch book and the Fantastic Beasts one thrown in. Under what circumstances did you allow your younger kids to advance through the Harry Potter series and movies?