Hope I haven't given you an impression it wasn't safe by what I said above. The runway is HUGE - I just wanted to save taxi time (the ramp is right at the NE end) and departed from half way along which meant we were still quite low over the fence. For what it's worth I never actually had to do any serious performance calculations for the whole trip - it just wasn't hot enough to matter. At that time of year anywhere high up is quite cold.