Are they able to solve simple logistics problems: How do they deal with missed trains or planes? how do they deal with lack of seats when we go to eat at a busy restaurant? how do they cope with rain, snow, excessive traffic, or crowds if we need to hail a cab? How do they treat bar and waitstaff? how about hotel staff? Are they able to book and change rooms in a sold-out hotel? How fussy are they about limited options for a late night meal? lack of internet? flat tire? a massive brawl nearby? road closures? power outages?
If you want to test someone's will to survive, in this day and age, put them in the stadium part of town immediately after the big game and watch them fetch for themselves and compete for food and transportation, not to mention personal space, with hordes of drunken and volatile masses.
The ones who whine, wince, or the least bit annoyed or confused should be dropped like dead weight.
[Edit: s/smirk/wince]