The political themes in this are nicely done. I really like the idea of the cultural borrowing back and forth between the Muggle and wizarding worlds. And also the fun little jabs at some fandom cliches (Snape alive, Snape the vampire, etc.).
Your characterizations are all fantastic, but I especially love your take on Augusta here. She's as rigid and controlling as she is in canon, but you've also allowed us to see greater depth beyond that. The old ladies getting drunk and scandalous was great fun too. ;)