I ranch and guide hunters in area 24 and every year I have to explain to hunting clients that smaller is better when it comes to rifles. 300WM is overkill by a long ways. I always suggest that clients bring a .243 or 25/06, as that is all the gun that is needed. I have seen too many times, hunters thinking that more gun means they can take longer shots. Most hunters will have a rifle that has more ability than they do as shooters and then they get mad when I won't let them take that long shot. As a guide, I owe it to the game to make sure it is harvested in a clean and humane manner.
Last season I had a hunter get mad when I wouldn't allow his son to take a 500 yard shot at a goat. When I said no, his response was, "Well the gun will reach that far". When they arrived the day before, I took them to the range to check "0" on their rifles, which also made Dad mad, because, according to him, they had zeroed everything before they flew up from the east coast. Anyhow, while at the range, I let them shoot my rifle and Son said he had never shot at anything over a couple hundred yards. There was no way on earth I was going to let him take a 500 yard shot.
Another factor that people are not usually prepared for is the wind. Again, just because a rifle will punch through the wind doesn't mean the shooter has the ability to judge his hold. What would be a clean shot through the boiler room on a calm day can often mean a gut shot or hip shot animal goes off and suffers until it dies or is killed by coyotes.
It is a point of pride to be able to shoot and harvest game with a nice long distance shot, but rarely does luck play a role. You have to practice to make those shots. And not only does a person have to practice, but they have to practice in similar conditions. Being able to shoot 500 yards on a calm day is a hell of lot easier than shooting 300 with a 20mph crosswind.
OP, don't overthink the rifle or optics. A .243 or 25/06 with a 3x9 scope is more than sufficient for cleanly harvesting an animal. If you are using an outfitter, call him and see what he suggests. I bet he will say the same. Don't worry too much about snakes. There may still be a few out, but the weather could also be pretty rough by then too, and they most likely will not be an issue.
What area will you be hunting?
Good luck and have fun.
Tex