I feel it weakens in just a year in unconditioned garage with extreme temperatures. I store my rolls of line in a closet inside. I feel it's good for years. If yours has had a lot of heat/cold and now has lots of memory I would pitch it. Probably some guys here that will dispose of it for you!
+1
It will last a lot longer in a controlled enviroment, especially in Texas, the constant changing temps over time is not good on any types of line. To make it last longer I would def recommend in a closet or room inside where the temps stay pretty consistent. If that is how it has been stored, I would not think twice about using it. I know of several of the Elite guys that have bulk spools of line sent to them every so often and it builds up pretty good, but all of them(that I talk to or know) keep the line in its original box in the top of a closet or tackle room.