I had wondered for a while if they found anything out via the placenta or car about the baby's condition that was with held.
I also, for some reason, thought of a story id heard a while ago about a woman whose newborn died and she carried it around as if it were still alive in a state of shock. Not saying thats what is up, just curious to find out what is. I cant imagine them leaving the baby unattended in this cold after all this time and energy trying to stay together.
I also think it was pretty obvious from the purchase of the tent and other items theyd be camping. I think there is either some serious drug or and mental health issues that impair their judgement and create issues like paranoia, etc. Hope that little one is found soon, and safe!