Aren't number 4 ("Never leave your vehicle") and number 13 ("rely on your own resourcefulness – don’t assume someone will be looking for you") opposite to each other? Number 4 assumes someone is looking for you.

Having pointed that out, I will add that number 13 could also mean "Don't just sit by the vehicle and wait to be rescued; build a signal fire, tramp out a big "SOS" in the snow, and with your copious free time, read and re-read your survival manual ."

Better to combine them - if you know or suspect that someone will be looking for you, then stay with the vehicle as long as possible. Be prepared to leave the vehicle and try to walk out (as a last resort) if you know that nobody is going to look for you, or that the searchers are going to be looking in the wrong place, or the search has been called off.

How do you know if the search has been called off? If I'm not mistaken, SAR efforts are usually scaled back if nothing has been found after 14 days (although this may only be for downed aircraft; anyone know for sure?), so figure out when the search is most likely going to start and add 2 weeks to that. ("I'm due back to work on Monday, my co-workers probably won't report me missing until Tuesday or Wednesday, so if the searchers haven't found me by 2 weeks from next Wednesday I'll assume they've stopped looking.")