learned this about elk and buffalo....
ice/snow can actually insulate hot meat causing it to spoil sooner
ideally you get the animal gutted and skinned to help cool off more quickly.
A big mass of meat can spoil in the center etc... due to hot spots, also in a cooler with ice etc...I think you need air circulating to cool off meat
Personally I think if you shoot an animal, and know its dead, there's no reason not to start the processing, even if that means working in the dark and til the wee hours.
gut it, skin it, hang it, get it to the processor or wherever you're gonna cut it up. I see no reason to leave an animal simply out of convenience, ie its late, youre tired, unless you're 2nd guessing if you made a kill shot etc...
if all you do is gut an animal, spread it open with some sticks etc....at least, help get air circulating in there.
while elk hunting this year, a guy shot/killed an elk at daybreak, left it there for a good 4 or 5hrs in the sun, waiting for his guide I assume? it bloated up etc...
I say take some pictures and get cuttin!