I recently picked up a large lot of EPP that expired in 1992. Thats 17 yeras roughly.
If was frozen all that time and is still performing quite good.
There is the very slightest shift toward magenta (but not bad and I expect much more) and from what I can tell has not lost any speed. I haven't done tests with a densitometer but it looks good and this film is fantastic for cross pross anyway so I think I did well.
It's always a crapshoot depending on storage conditions.
Another time I got some Portra 160 NC that was green that expired in 2001-2002 so...