Dude, you moved the goalpost. You've basically said even if a population is 100% vaxxed, herd immunity isn't possible if there are people coming in from other areas that aren't 100% vaxxed.
You've destroyed your Martha's Vineyard argument (think of the weekend daytrippers there in the summer). You've said San Diego and Texas can't reach herd immunity given the border crossing (which for them is a huge deal than lumping in Missouri's population to say 1 border crossing per 330 residents). You are also saying then for New York City herd immunity is impossible unless the residents of surrounding New York, Connecticut, and New Jersey are fully vaccinated (even though they also are overwhelmingly day commuters just like in Gibraltar).
You are saying that herd immunity is impossible while there is a large motion of people (even if those people don't stay overnight in the location, as in Gibraltar). So we've gone from 70%, to 85% to 90% to 100% to 100%+ everyone in travel distance to get to herd immunity. You may as well say there's no such thing until everyone in the globe is vaccinated because you know what, people travel. Do you ever get tired of pushing those big goals around the field???