Well lets face it, how many witnesses really do travel the world over. I traveled a lot on business when I was in. Mostly, did not even attempt to go to a KH. When I did I was generally ignored until I made the effort to talk to people, then things were OK. I think it is more to do with human beings, doing as humans do. There was never anything special about going to meet witnesses at their halls.
There was one congregation in Reno, Nevada (I live in Germany) where one brother was really nice and hospital, but thinking back now I really think he was a closet apostate. Unfortunately my business no longer takes me there.
So going back to the OP, people are the same the world over, except witnesses exclude everybody outside their cult. People are generally hospitable, but witness are not hospitable to non witnesses, and even witnesses are not as hospitable to other witnesses as other Christians are to other Christians.