One bit of information that I haven't seen anyone bring up before, is about the original prophecy (the Harry vs. Voldemort one).

Voldemort claims it is already fulfilled. But in an earlier chapter Snape claims that as the one for whom the original prophecy was meant, he will know when it is fulfilled, and it hasn't yet. So assuming Snape isn't either lying or mistaken (and Dumbledore is also present, bringing down the chance of Snape being mistaken), then that particular prophecy is still in effect.

Snape makes another very important claim in that passage. He claims that the 'Power the dark lord knows not' is not just a power that the Dark Lord doesn't know, but one he can't know. He explicitly rules out Harry's knowledge of muggle science as this power.

As far as I can tell, this pretty much leaves 3 candidates for "Power the dark lord knows not" - Love, as per canon. Unlikely since it hasn't been brought up, and unlike in canon probably doesn't have any special powers. - Partial transfiguration. Not sure thought if this is a power that the dark lord can't learn. Presumable if he studied muggle science enough, he'd be able to learn it - The patronus 2.0 & dementor scaring ability. This is absolutely a power Voldemort will never be able to learn, and thus in my book the best candidate. Assuming of course Snape isn't full of shit.

I don't see any immediate way to translate this bit of information into an action to escape Harry's predicament. But hopefully others can do something with this. It's probably relevant, and nobody seems to be talking about it. Especially since the prophecy implies that 'the power the dark lord knows not' is key to defeating him.