There's no "long haul" out there. I've never been in that part of the park, but from looking at the map I would say the only likely survival there would be to hunker down and push the button (the backcountry equivalent to calling 911--not an option back then.)
If that were not an option I would wait for nightfall, keep all lights and navigation, space blankets, sun umbrella and the jerry can of water, abandon everything else and try to hoof it. I would consider success unlikely. Given the supplies they had I would consider survival impossible.
It depends on the situation. If you have had a breakdown and have to hoof it (which normally shouldn't happen anyway--you should be prepared to hold out until you're reported overdue and they're looking for you) you could be in a situation where you know ahead is shorter than behind. That assumes you know where you are and what the roads around are like.
If that were not an option I would wait for nightfall, keep all lights and navigation, space blankets, sun umbrella and the jerry can of water, abandon everything else and try to hoof it. I would consider success unlikely. Given the supplies they had I would consider survival impossible.