SHTF whilst on holiday/vacation?

That would definately be the worst case scenario (short of the Earth exploding) in shtf. I thought the same thing, like if I was on a cruise. I would imagine the only thing you can do is rely on your skills (if any) to survive. I think stuff like that happened in Haiti. If I were in the city I would go to the suburbs. I would also try to have enough local currence on hand to at least get water. If I were stuck in an airport waiting for the sky to clear I would just wait it out.

Thankfully, do to my lack of finances, I won't be traveling overseas anytime soon

We are going to Jamaica in August (love that place) with our kids and our sheeple friends and their kids. Obviously, I can't bring any of my "real" preps with me (airline regulations and local laws and all that nonsense). To prepare for disruptions in international travel, I am going to bring a week's worth of expenses in cash, make sure my credit cards are accepted locally, and I will keep checking the news while there. For everything else... we will just have to see what (if anything) happens, and go with the flow when it does.