Like others say, you have a pretty good set-up and I wouldn't change much. In my view, your weak spot is the boots. Like sitka gear, miendles are not made for stand hunting. You need at least a 800gram boot or even some felt packs. Somebody mentioned sorels, which are a great option and pretty reasonably priced. You could also check out the schnees pack boots, which are more expensive and a bit better if you do any walking.
I suggest you upgrade your boots, and follow advise above around hats, neck gaitors, & handwarmers. I have chronic cold hands and while I still hunt mostly, I will stand hunt for periods. I have a pair of gore-tex ski mittens (black with rubberized palm) and wear a glove liner underneath...and always have set of handwarmers in the mitten.
The only other thing I have started using as a layer is a synthetic 'puff' jacket or a down sweater. These are simply awesome - warm, super light & pack down to nothing when hoofing it.
Good luck and congrats on getting into such great shape!
