I agree, the probability of survival is getting low, because of lack of food. I think SAR teams would be best able to assess the survivability factors.
I think searching for a living person, vs searching for remains, are two very different things. When SAR teams look for a living person, they try to cover a lot of territory quickly, make lots of noise, and keep heads up, eyes open for distant movement and listening for calls for help.
As a result, they sometimes walk quite near to remains hidden by bushes, etc.
But they are looking to rescue someone alive, and from my observation, rarely commit much time and effort to finding remains unless they have narrowed down a very small area to look in, like the size of a city park.
JMO