I can only speak for the Typhoon fleet, but that scenario just doesn't happen. Purely my guess, but around 95% of EGRs can be carried out where the aircraft was parked. Anything above mid-power is rarely required. You're not going to A/F, refuel, download the brick and decide on a recovery plan in anywhere near 30 minutes. Fault diagnosis? Spares? Manpower? And a Land Rover?!