I would recommend buying or borrowing a scale. Make up a list and weigh ALL you gear (including your rifle, bow, boots, etc). I've been taking self-guided trips to Alaska the past 10 years. It's essential for me to cut weight and bulk to save on flight baggage costs....as well as weight limits flying into dropoff locations.
After weighing all your hunting stuff....figure out which items weigh the most. You will find out that it gets fairly expensive in a hurry cutting weight/bulk..especially if you buy quality gear! Generally speaking your rifle/bow, pack, tent, sleeping bag, sleeping pad, boots, spotting scope, tripod, coat, raingear, etc are where you can significantly cut weight and bulk. You are on the right track!
In regard to sleeping bags. I only weigh 145 lbs dripping wet. I get cold a lot easier than most guys. I pretty much take a 0 degree bag with me everywhere I go in early fall/winter. Obviously some guys need a warmer bag than others. It's possible to add/subtract layers depending upon how warm/cold it is. I generally am warm when I go to bed and often cooler by morning. It's a bad idea to have too many clothes on when you first hit the hay or you may end up pretty damp/sweatie by morning? Everyone is a little different so figure out a system that you are comfortable with!