I like it!
I went ahead and threw in Layth today because I figure if we're going with that timeline it's probably best to focus on the barons figuring it out the next day (I was kinda planning for them to have another meeting then anyways so it fits cx [s]plus Layth came just in time to crush their hope a little more ^^;[/s]). Since John's coming in with the supplies as well, I think that timing will work out pretty well since they were supposed to arrive within a week or so.
 I like the idea of them choosing something a bit harsh. Figuring Mia wouldn't really agree with death, so maybe it could end up being something like cutting his hands off. That would be enough to freak both him and Penelope out xD Then John can just pop and be like 'hey maybe don't?' xD