I think it is a known risk that nobody is denying. It would be great if the games patches is universal (not tie to your console) but again, it might be the case. Because I see a page somewhere in here that give links for patches (but not all games) I think you should be able to get that and ftp thru the demo installer and then install as normal.
Haven't tried that though. But going through the normal online path is definitely NOT the way I would do if I were you. At this moment it is very unclear that whether Sony will do what Micro$oft do last time with XBOX live account banning.