This is interesting and unusual. I like the way you've thought about the way things might have gone wrong with the children, and the ways in which they'd go wrong between Harry and Ginny. You acknowledge that really Harry is pretty thick, even though he tries, with love and goodwill – in public as well as private life (and that the Weasleys are not an entirely successful or healthy family, too – you have me being very sorry for Hermione! peripheral though she is to Harry's story).
You've found a neat new way of saving Snape: congratulations! I'm not sure I believe in a Snape content to be a cook (however good), but I can see the lure of a quiet and retired life, where he is not known and therefore will be evaluated for what he is, rather than on preconceptions – provided that he can give up ambition and the desire for recognition. Turn into almost a different person entirely, with greater capacity for contentment, even if until now he's been denied real happiness – not that he'd be expecting that. He has respect, and a place, and productive activity in which he can excel. Maybe he grew up in that curative stasis. He certainly is far more adult, now.
The solstice had passed; the light would be returning - Yes!