Advocate is intended for use every 4 weeks. Beyond that it's not going to give much, if any resistance, to fleas. (I've noticed that, irrespective of the product used, my cats start to pick up fleas a bit before the end of a four week cycle, so it's clearly not going to work beyond that period). However I don't bother with flea treatment for two of my three cats during the winter months anyway, as only one of them (who has a flea allergy) suffers any real problems with fleas outside of the warmer months.
Standalone worming treatments seem to keep on working for several months, so it might be that the worming element of Advocate will work beyond the 4 week period too. (I tend to only worm my cats when I notice problems).
I know what you mean about 'kerfuffle' though. My cat with a flea allergy should have had his flea treatment renewed a fortnight ago but I've not managed to catch him yet!