Same at JFK. B767 flying to Europe; CAT 3 airfield, TAF CAVOK, minimum fuel. Contingency was >30mins + long diversion. Number 45 in taxi queue. You work it out. 90 mins taxi was more than 1000kgs = 15mins flying. Shut one down for SE taxi. If not then we would have departed less than plog even after changing to closer diversion.
Anyone shut down an engine to extend holding time? e.g island holding or unexpected delay. FF with one off is less than all running.