As a practical matter, we use metric for many things in the US. The fact that we do not force everyone to change their customary units to metric really seems to irk some folks, but mostly outside the US.
And, the best, is “football pitches” which is often used by the news to describe large (but not too large) lengths.
I think we'll soon be left with the only remaining imperial bits being speed, long distances, and pints of beer - none of which seem likely to go away any time soon
For pints (only really used for beer and milk), we still use an imperial pint but it's officially specified in millilitres (568ml) and this will always be printed on packaging.