There are lots of "hop aging calculators" out there, here is one. You can see the effect of temperature on stored hops, it's fairly dramatic: for an example, Cascade stored in a barrier package for 500 days at 0°F would maintain 85% of the original AA, but at 70°F the hops are down to 36%...
Then they should be in pretty good shape, at least wrt to alpha acid content. As long as you adjust your hop rates to account for the losses (again, referring to any of many calculators) there shouldn't be much difference between fresh and your frozen/aged hops for bittering...
Cheers!