imho refrigerating helps a lot. especially with peel apart film, I recently had b+w film from 95 which was still quite o.k. but I also had sx-70 which was 4 years over the date and still fine.
the batteries are a problem indeed. yes, it's possible to swap the battery from a recent empty cassette with a not working one. it has to be done in absolute darkness, at least I had success with this twice. the battery was good for a whole second film cassette. working it out with an empty cassette in daylight helps a lot.