Do what Sirius said, you may be surprised.
I have some 8-year-old Polaroid OneFilm (color, probably Agfa). When I tested, I bracketed exposures, taking the same picture at box speed, 1-stop over, and 2-stops over. I decided it was still best at box speed (400). However, there was a color shift from the age, so I tested with an FLD filter (this time at box speed, 1/3 stop, and one full stop); with the FLD it works fine at box speed (the filter effectively slows it down a bit). I found the same to be true of some Konica Centuria Pro 400 I have, needed only an FLD to correct color.
Keep in mind, this is just my experience, and I tested a bit to get here. (Otherwise, it seems the general suggestion is 1 stop for 10 years). I don't use either of these for "important" pictures, but it only took a total of three rolls to get results I'm happy with for general use.
On the other hand, I've found Kodak and Fuji color films to be more robust.
I also had a roll of 10-year-old Tri-X (B&W) and gave it an extra stop of exposure - it was over-exposed. Black and white is quiet resilient.