What's your most disastrous holiday story?

In the '80s my family piled into our brand new (maybe two months old) Plymouth Caravelle for the long trek from central Saskatchewan (Regina) to northern B.C. (Prince George) to get to a family Christmas gathering.
In the middle of nowhere, during a mild snowstorm, the transmission just stopped. The engine worked fine. Everything in the car worked fine. Except the transmission. So in the middle of nowhere, and in the middle of the Christmas season (this becomes important) we were stuck in the middle of nowhere.
Now thankfully the engine worked, so we could keep the car heated. And the gas tank was full so it would be a long time before we'd face actual cold. My mother and I, thus, were left in the car while my dad bundled up and started walking to the nearest town (according to the map) to get help. His idea was to hitch-hike, actually, but ... Christmas. There was no traffic. So for hours my mother and I sat in the car getting increasingly worried as the sky darkened before, finally, we saw headlights off in the distance in the direction my dad had disappeared in.
It was a tow truck. My father had reached the town, found out that no tow truck operators were even in town and had to get someone to drive him to the NEXT town to find a place that had a tow truck in operation. We got hooked up and pulled onto the flatbed and driven to where the nearest Chrysler service centre was.
Now it's indisputable that we were under warranty. The car was two months old. If we'd driven non-stop for the entire time we'd not be anywhere near out of warranty yet, but this didn't stop the Chrysler guys from trying to deny us warranty service. (There were complicated reasons for this caused by Chrysler's bizarre incentive structures for service.) It got to the point of my father calling a lawyer and just as that conversation started the service centre collapsed and decided to do the service as required. AND supply the loaner vehicle (which was a New Yorker because that's all they had on the lot at the time).
It took a while for it to sink in that had the engine failed we'd likely have been either dead or seriously hurt by the cold.
I've never even looked at a Chrysler product after that. Not just because a brand new car failed so utterly (shit happens) but because the company's shenanigans around service are simply unacceptable … and I do not forget, nor forgive, such behaviour.
- Holy shit mate that's like something from a film! That could have gone really wrong.
  Shows the importance of always having emergency supplies on the car
  
  Oh, we had emergency supplies. And plenty of warm clothing. But yeah, it was something that could easily have gone totally pear-shaped.
- I will say the one time I bought a Chrysler, the sales experience was fucking awful. Presumably that's in the dealership not the car maker, but it was bad enough I'll never buy another.
  Still driving it, though.
  
  The dealership in our case was fine. They even apologized profusely for that Albertan service centre's behaviour. But if the core company is vile, I don't buy their products. Neither my parents nor I bought a Chrysler ever since. My father bought two Toyotas and a Nissan. I bought a Pontiac and an Acura. My stepfather buys Nissan only. To his dying day my father refused to even look at a Chrysler as an option. They made literal life-long enemies with that.

When I was much younger I arranged to go on holiday with a friend I didn't know well (mistake 1). I then ended up developing anxiety cos of work but thought I'd go on holiday anyway (mistake 2).
Friend turned out to be a total bitch, and was really angry with me for not being able to go clubbing with her every night. She got really catty and nasty and I spent all week in the hotel room watching telly. 0/10 would not recommend
- Yeah, you have to be really careful who you choose as a travel partner. Bad partners destroy any trip.
  
  Yep lesson definitely learned!

I ate a fish dinner once. I still remember it to this day

I have friends who live near Niagara Falls, and I was going to visit them on Thanksgiving, but there was a terrorist attack that day in the same place, which deterred everyone via chain reaction.