I could not find bunkerage for a DD, but it obviously would be much smaller than that for a BB.
I imagine the Navy worked out how best to do UNREP, duh. It is interesting. Iowa class cruising range:
9,600 miles (15,000 km) @ 25 knots (46 km/h); 16,600 miles (27,000 km) @ 15 knots (28 km/h)
25 knots is not flank of course, which is 33 knots. That is about 700 miles (statute) in 24 hours at 25 knots, so they can maintain 25 knots for two weeks.