we must first postulate that Harry/Hermione get out of this situation and that one of them is able to contact McGonagall while evading control or surveillance.
Perhaps Harry could will a patronus to take an extremely small form?
Persuade enough Muggles to take her seriously
Doable, given enough time. If she is morally flexible enough, she could simply memory charm those at the top of the command chain, but... this isn't the sort of thing I'd imagine her doing.
Anticipate Voldemort's intentions and avenues of attack
This is a problem. Unless Harry explains it to her, I don't think she will understand just how bad the situation is.
Explain these to the Muggles in sufficient detail that the Muggles could devise countermeasures (McGonagall certainly can't devise Muggle countermeasures for them)
I'd seek advice from Muggleborns. But actually, in canon the muggle prime minister at least knows about the existence of wizards. I wonder if the muggles already have a (top secret) plan in place for what to do if wizards attack them?
Do all this in the time frame before Voldemort could take over magical Britain, not to mention whichever Muggles McGonagall has gone to for help
This is the big problem.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 112.
There is a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: