Rob, don't worry, if the sockeye salmon closed in a couple of weeks from now, you would not have missed anything.
I think you may have the wrong perception about the Fraser River sockeye salmon fishery, it is not particularly flyfishermen friendly, and the fish are not taking the fly aggressively.
What I would recommend is, to focus on getting out for a few trips between mid September and early December. The salmon fishing is going to be fanastic between that period, especially for a flyfisherman.
During this period, you'll be able to flyfish for coho salmon. The type of fishing is also quite unique, mostly done in moderate to no flow waters. You can see the fish following the fly to you as you strip in the line, it is exciting.
In November, flyfishing for chum salmon can also be very good.
So no stress if you are unable to get out this weekend, unless you are leaving town soon.