I also have no clue about what's going to happen in October, BTW I can add a few words to what Cova has said. During canonization ceremonies, it's true, many people come to Rome, but it's also true that they are organized by the local churches, and often they sleep in churches here in Rome. So it shouldn't be so hard to find a place to stay, at least not more than usual. As for myself, I would try to stay away from the Vatican area in those days, even though it's not easy since I live 5 minutes from the Vatican... for Father Pio they closed the whole area and didn't want to let me go out!!!!!

Ciao Flavio in Rome