R 21
It has taken me 5 days to get back from Basrah to Brize in the past, so I am afraid that, like many, I have little sympathy for your 21 hour epic!! I have met people who have spent their entire R&R period simply in transit!
The entire system seems to be coming apart at the seams, despite the best efforts of most people within it, be they aircrew, movers, etc. This is simply because they are all being asked to achieve too much with too few resources, and have been for several years now!!
It is not rocket science. Spend more, do less, or carry on with the same shoddy system, those are the only options available.