Pork fat's freezer life is about 6 months before it starts to go bad. It will develop on "off" taste even if frozen/vacuum packed. I use 10% beef ribeye trimmings to mix with venison burger.
We routinely find a lost package of venison hamburger at the bottom of the chest freezer that is a couple years old and is still as good as the day it was frozen. Double wrapping in freezer paper is also a key to long freezer shelf life.
