At one point I actually thought about doing that but I can wait. I'm a firm believer in doing something right the first time. Besides, I already know what 215/45/18 looks like on 8.5 wheels and disliked the look. I don't mind a mild stretch, but that's too stretched for me.
As far as rubbing, I'm going with around -2 camber and shaving (not rolling) the fenders. So there won't be any rubbing.