A LHR-TIP trip last December, interrupted by the snow, the A320 had about 10-20 people (fading memory) and we were waiting for several hours for the de-icer - I was increasingly hopefuly BA might just cancel the flight, but we took off anyway.

My friend had almost a 747 to himself to Argentina one New Year's eve many years ago, still he wasn't allowed an upgrade to the next cabin