I have only done one bivy elk hunt, it was one of my first hunts after moving out west and it was a learning experience. I packed way too much food and water. I didn't have a firm idea on where I was going to find water so carried alot with me. You can't carry enough, so make sure you have a good plan for finding water. If you are lucky enough to live close to where you will be hunting or are planning a scouting trip, cache some water now and then you won't be stressing about it. Also thought I planned out meals pretty well. I had a large gallon zip lock bag with one days food in each bag, and I didn't eat everything I had packed. I do not the mountain house meals, which I learned on this hunt. Since then, I have been spending alot of time on lightweight backpacking sites. Looking for recipes I can dehydrate myself. If you have a dehydrator, you can eat pretty well and not pay the factory food prices. Try what ever you are planning on eating on this hunt now, to make sure you like it. Day 2 of an 8 day hunt is not the time or place to learn that you are not happy with menu selection. I took to many optics along, 10's 15's and spotting scope, with tri pod. I used the 15's a little bit, but all I really needes were the 10's and honestly my old set of 8's would have been ok to. I am not a trophy hunter and 10's are more than enough to let me know if an elk is worth taking off after. I was solo hunting and did get some use out of an elk decoy. I didn't back the poles, just had some 550 cord and quick clips that I could rig to a tree branch in a hurry. I can't take credit for the 550 cord idea. A friend of mine showed that to me and it worked out pretty well. Depending on how high you are hunting, it can get cold at night and in the morning. I took a 32 degree bag and slept in long johns and winter cap. It worked for me and thought I was cool some nights, I slept ok. I had a solo tent, but the weather was clear for the whole hunt and I never set it up. I don't know about the letting the warden know where I was going. My wife knew what unit I was hunting in and I told her what trail head I had planned on using, but once I was hunting I carried my camp with me and moved around quite a bit. I packed a book, but didn't read as much as I thought I would. If it was dark, I was eating or sleeping and if it was light I was looking for elk.
Things that I was glad I took. I good and bright headlamp. Baby wipes, can't have too many. Duct tape. tweezers. ibuprophen.
I was ultimately successful in this hunt, I managed to shoot a nice 5x5. My first elk. It is the rack in my profile photo that my son is holding. I ended up shooting him about 2 hours from my truck on the last day as I was headed back down. I packed out myself over 16 hours and 3 trips. I used an eberlestock bluewidow and the pack did ok. It was the pack I hunted out of all week. I do wish I had a freight hauler in the truck that I could have switched to after the first trip. Treking poles with a loaded pack were very helpful. I didn't use them much while hunting, but they were worth it on the way out, especially down hill trying to step over fallen trees until I got to a path.
What I learned in that I am an over packer and need to really cut back. If you want to find out if you are, pack all your gear including food and water and do conditioning hikes. You will quickly start stripping your gear list down to just the essentials.
This seems more like a list of what not to do, maybe you can take something from my mistakes. I am planning on doing better next go around.