These questions and answers are posted continuously in reverse date order. Hence the first questions are always the most recent. Rolls of film can last even longer reaching greater than 10 years. At 4 degrees C it is rather more although how much more has not yet been tested.
Sheet film behaves similarly to the plates and rolls are again much longer-lived.
At 20 degrees C it is superior to one year. Practically the optimum storage temperature for all materials is 4 to 8 degrees C at low humidity. Note that rolls of film that have been stored for many years frequently have a 3mm-5mm stripe of damaged film at each extremity along their length. This is due to the interaction with air. Hence if your aim is to keep Slavich film products for very long times it is better to stock large width rolls.