Whoa: Spoilage depends on several factors. Air temperature needs to be below 40 degrees, to keep any meat from spoiling, or else you have to be in thin, dry air, that freezes every night, like happens at higher altitudes. In dry conditions, the bacteria can only survive in the soil, or plants, as few as there may be, and of course, in and on the body of the animal you kill. And on you. But bacteria need heat, moisture, and food to survive and reproduce. Moose tend to be a low land animal, but not always. If you are huning in the early Fall and its hot, then spoilage is a serious concern. You will need to be prepared to pack ice, dry ice, or have some way to cool the meat down quickly to preserve it. Because the moose feed and live in swampy territory, there is all the moisture in both the land and air needed by bacteria. And, obviously with a caracass that size, there is enough food for millions of bacteria to feed.
The best tip is to time your hunt when it is cold enough that the " no-see-ems " are not out. If you have to hunt wearing a nead net to keep the bugs from eating your alive, You are going to have trouble keeping that meat from the bugs, and from bacteria unless you have access to a cold storage facility within an hour. A moose shot after the first snow fall, even if the temperature is rising, is the smartest time for taking these animals. The cold not only produces the snow, and reduces air temperature, but it also kills the bacteria in the air, and on the plants, and ground. It also dries out the air until the temperature gets above 45 degrees.