Well, if you weigh in or not doesn't really affect your weight progress if you keep doing good. I say enjoy your vacation, register your food to the best of your abilities and think twice before you do any "dumb stuff". Then you're much more likely to come home to a reasonable weigh in.
Also, and this is just as important, ENJOY YOUR VACATION! Make sure you live life while you can, but try to be smart about it.
"Losing weight is never about eating as little as possible"
"Eating enough, moving more, not eating stupid s**t = losing weight."
"Do. Or do not. There is no trying."
- Master Yoda.
I started my weight loss journey on October 4th, 2010 - and this is what I have accomplished so far: