It's likely that they will still be pretty good, if they truly have been frozen the whole time, but impossible to say for sure without a test.
Factors working in your favor: Slow film (less fogging during storage from cosmic rays), 35mm (no backing paper to cause issues), sealed (better humidity control), frozen
Factors working against your favor: Pro film (designed to be used fresher and quicker than consumer grade)
Try loading up one roll into a cassette and doing a controlled test in stable lighting with a known-good camera, with 1/3 stop bracketing of exposure.