Lots of my English and Scottish colleagues have parents/older relatives who have retired to Spain and Portugal. If they are younger and looking for an "Anglo-Celtic" culture, Australia would be a better bet than the UK. Folks don't realize but Americans of English descent are a small minority of the US population as a whole, and the white population in aggregate. There are more people of German, Irish, and Italian ancestry in the U.S. than English.
BTW: I have more East Indians within a five mile radius of my house than anyplace in London. Don't have a problem with any of them.
Americans of English (and especially British — English, Welsh, Scottish, and Irish) descent aren’t all that small a minority in the United States. It isn’t the largest ethnicity (German), but it is still one of the largest.
i.e. 5% of the American population is still over 25% of the English population (since it’s around 25% of the UK population).