i shot medium sized cow last year first day of 4th rifle season about 2.5 miles in from parking spot. a little bit of up and down terrain. pretty open aspen groves with a trail for about 75% of the way. broke down and hung game bags first eve after about 2 hours of cutting. took first load of daypack, rifle, and first meat bag of backstraps and tenderloins. low of 30*, highs around 40* next day.
one load of each back ham (bone in weighed 45# each), then both boned out shoulders and ribs was last load. finished before dark second day and stayed the night to eat a lot and refuel my body. this was not a very bad packout for a solo elk hunt. a bull that weighs close to twice as much in a hotter environment will be a bit of a strain (worrying about spoilage and trying to go quicker and heavier....) but i am going to try this year on my first rifle either sex elk tag! it will either be a bull or a calf... or the first legal elk i have in my crosshairs.
Plan well, train as much as you can (if you are from sea level i have no idea how you can pull this off! i live in CO and can't imagine what this air does to flatlanders... my brother is a triathelete from sea level and it crushed him at the end of a 5 mile pack-in for mz deer hunt).
if you have a friend/hunt partner it should help the mental stress but try to embrace the suffering.