I'm not actually around on the dates mentioned BUT.... I see no problem at all. Personally I would move Heaven and Earth for Dreamflight, in this day and age it gives me a REAL sense of satisfaction to be doing something for those less well advantaged. ALL OF MY COLLEAGUES FEEL THE SAME.
People to speak to... Make SURE that you ring the LONDON FMU (at Swanwick) the day before, and the watch supervisor at LTCC West Drayton. They will be more than happy to help.
Rgds BEX