I've had hops stored in a similar way in the freezer. I go as far as to wrap the bags in Al foil to keep out all light. After around 6 months I noticed a decrease in the nice odor, even after warming. This was noticable with Cascade and Cenntenial. The citrus just wasn't as strong. Then again maybe I had a cold that day. The beer turned out great. I try to use hops stored in this way over the course of a month or so. I've just begun buying in bulk, so that may change. I may find someone with a vacuum sealer and break down the pounds to a few ounces at a time.