[The Grill at Clemson Marina](https://clemsonmarina.com/the-grill) is ~2.5 miles from the field so not really walkable, but those with folding bikes could reasonably make it.
Crew car is first-come, first-serve, and it limited to an hour. There's a "rental fee" if you keep it for longer than an hour. Also, gas is a little bit of a drive, if you want to fill it up before returning it.