Its an interesting idea, ive actually been to two in that top 20, morocco and costa rica. I did know a little bit of spanish for the costa rica trip, my high school spanish came back slightly and google translate was helpful enough. Moroccan arabic is really a niche language and found english took me pretty far, i actually didn't bother to learn any arabic for that trip.
Maybe you'll find an interesting travel destination where that's not the case by sorting this list by percent English speakers, ascending: https://en.wikipedia.org/wiki/List_of_countries_by_English-s...