Shulchan Aruch says an Israeli Jew who is just visiting non-Israel should not work in public on the second day of Yomtov so long as he is in "yishuv" (and commentaries explain "yishuv yisrael") -- a city inhabited by Jews.

I think there are places in the United States where you could draw a hundred-mile radius where you won't run into a single yomtov-observant Jew -- but you will run into Jews who don't observe. How about in those places?