Though most disagree with my system....I use a 300 yard zero. Assuming the bullet is near 3K muzzle velocity and of a fairly decent BC. It has worked for my wife and I for roughly 20 years. With the above ballistics in mind, we're good from muzzle to 400 yards on big game. We'are approximately 6" high at approximately 180 yards.....which means just hold a bit low @ 150 - 200 yards. If the shot appears a bit long, we're only around 9" to 10" low at 400....holding a little high on the longish shots, will easily keep you in the lungs. I find this easier than estimating how much holdover at 400 yards with a 100 yard zero. I find it easier to hold a "dollar bill" low @ 180 yrds, and a "dollar bill+" high @ 400 yards. With a 100 yard zero, on the 400 yard shot...I must now estimate a 25" holdover. Which is easier to visualize in the "heat of the moment" a dollar bill or 4 end to end! We used this system, quite successfully prior to our owning range finders, and now...if time does not offer the opportunity to use a range finder. Your biggest challenge, is to roughly estimate the distance. Beyond 400, proper ranging is exponentially important with increasing distance. Beyond the 400 yards is where your drop charts are needed....more for the distance than the elevation changes. You will also likely have time to use the rangefinder and set-up for the long difficult shot!
If your trying to condition yourself for your hunt, you have the perfect opportunity to learn range estimitation. When on a training hike/run/walk, pick out an object ahead, guesstimate the distance.....then verify with your range finder. Do this a lot, on different sized objects, under different lighting conditions. You may be surprised, how accurate you can become with diligent practice. Technology is great, when it works and you have time to use it!
Obviously, "aim small - miss small" is a great shooting tool, but you're not shooting for tiny groups. I suspect that your POI changes will not be dramatically changed from 4000 to 8000 feet. Try not to load-up your mind with non - essential information. At the time of the shot, your physical status, atmospheric conditions, and potential stress of the situation are likely to affect your shot, far more than a few thousand feet of elevation error/change! These are just my opinions, and hopefully some of it you may find helpful! memtb
All of this was stated.....assuming you rezero when you get here @ around 4000feet of elevation! I neglected to put that originally! My apologies!