I hunt alone often. Just did 5 days (deer), about 5 miles in & 7,500 to 8,000 ft. altitude. Going in, all uphill, so coming out would be downhill. 5-1/2 hours in 14" of snow going in was rough. Two hours walking out w/o stopping. Last year I spent 9 days on a ridge alone.
I was right there where I wanted to be. Only other hunters with horses were seen and they didn't even get to where I was till after noon. One difference was, they were fresh and I was physically spent from the hike in, although after a couple nights, I recovered. I had to walk about 1/2 mile to a spring for water but later just melted snow, which used up a fair amount of fuel but was way easier on my body. With a long hike in, you'll be wet from sweat. You'll need time for your clothes to dry or dry clothes to climb into bed with. I had neither. It was just dark when I arrived and I didn't get into bed until 10:00 pm. I was cold and wet the whole night. A work problem caused a late start that day, hence a suck-o night.
One thing about hunting alone is the possibility of injury. You have to be very conservative about your decisions. Stepping over logs and such are fairly risky things and you can't commit to a step unless you know it's not going to end in a twisted or broken ankle. Increase the the risk when your tired or in a hurry because it's getting dark. I know a guy that broke his ankle packing out meat. Just one step around a log and "snap". He had to crab crawl 150 yards back to camp where other members got him out and to medical attention, and they also dealt with the meat and camp. If he was 5 miles in and alone, he might still be there. That should weigh heavily on a person's decisions.
Oh, and if your going to hunt elk, two guys are probably going to be a wreck just packing meat so doing it solo plus packing your camp would require a more effort than what your body wants go give you. Seriously... you mind say's "go" but your body say's "no".
Other than that, my pack was about 45 or 50 lbs. I was very tired + sore feet, and if I had to pack out another 100 lbs., I'd be a wreck. I could lighten it up a little bit I guess. Oh, and I didn't see a single deer and I hunted hard and binoculars helped me cover quite a bit of ground. As they say, "past results are not indicative of future gains".
Probably the biggest factor about hunting alone is, will anybody miss you if you die? If you have a young family that need you or want a family, you should consider that. Even an injury may affect your income or employment status. This is supposed to be fun. A lot about life is just managing risk.