Yes, this is always the consideration. No one can count on a rescue. If the conditions are adverse in summer, even, SAR won't go out because of the risks someone could get hurt or die (which happens.). SAR helicopters crash, rangers fall down crevasses, rescuers can permanently damage their backs, etc. So, wind, fog, heavy rain, snow, soaring temperatures, forest fires, no SAR. No risking a life to save a life, but especially if the odds are "recovery" not rescue. IMO in ED's case, the odds of a rescue were very low because of the time that elapsed and the frigid night time temperatures.