RE: How cool does it need to be?
Well I know of one time that my mother shot a little forky bow hunting and the temps were mid 70's and lower 80's during the day here In Minnesota. The temps didn't drop much that night when we didn't find it. I think the temp was 62 degree's when we started back on It that morning. At 4:00 pm the day after she hit the buck we finally found the buck (high one lung hit). We kept both the of the hind quarters and some of the back straps toward the rear. I know If we would of found that buck In the morning we would of been able to keep the whole thing.
We've also let many bear lay overnight In 60 degree temps not knowing exactly how good of a shot we had. Bear have 100 times the fat of a deer and In most of the cases the bear meat was good the following morning.