Hi neighbor, I'm in the same boat.
A little over half of the Neurology programs I am applying for are categorical. For the rest, I have on average two or three prelims per city (sometimes one, sometimes five or six). This means that I am applying to a significantly larger number of prelims than actual advanced programs. My plan is to only accept interviews to prelims in cities where I already have advanced interviews, or where I have a cluster of advanced programs that I'm applying to. For prelim invites that come early, before I know where I'll be interviewing for advanced, I will probably just accept them, and if I later realize I need to cancel them, I'll do so at the earliest possible minute.
Also, I'm couples matching, so I am trying to do whatever I can to make sure I don't have to scramble and be apart from my fiancee (i.e. take my story with a grain of salt). Chances are, I will wind up ranking the categoricals much higher for this reason, but I don't want to completely handicap myself. It's a shame that some of the best programs are categorical - it's like they know they can get away with it.