Taking out the entrails ASAP will aid in cooling soon after the duck has died. Overnight in that kind of weather probably won’t hurt. (I have had ducks freeze before I got home) The taste is improved if the entrails are immediately removed. A couple of days, Hmmmm, I don’t know if Id eat it. Trust me, the nose knows so if it does not smell good don’t eat it.
In days gone by it was common for waterfowl and small game to be hung for several days, entrails removed with the skin on to age the meat. I have done this when weather permits and I can tell you an aged duck is very good. But be careful, an upswing in temp can ruin your game.