I’ve had some old polaroid B&W film in my film fridge for years. It says on the web that the last production run of this film was in 2008 with an expiration date of 2010, but Polaroid made a bunch and refrigerated it and kept selling it for years. Most places don’t have it anymore, but you can still get it on Amazon for about $20 per pack (10 pictures).
Anyway, the four packs I have expired in Feb 2007, but I’ve had them in the fridge since I got them. I pulled out a pack to see if they are still good and they are! I shot it at the speed it’s rated at and developed it according to the instructions and it still works perfectly. This was taken with my 4x5 Shen Hao camera.