When you press the throttle there is a click at the bottom of the travel which is the kickdown switch. If you press the throttle to just before the click it won't hold gears quite so long.
In terms of reprogramming that will require the transmission ECU to be reprogrammed - I seem to recall a place in Kent can do this.
Isn't that the same as LK was saying?
i.e. Pressing the kickdown is more likely to drop to a lower gear and hold it for longer. Just before the kickdown button will be less likely to change down and will change up a tad sooner.
… do you really want it changing up at 3000rpm so you die - or rather make good progress and enjoy the trip out with your loved ones?