Sorry to be a kill-joy but can't help thinking "Why?"... what is the point of spending all that time, pain and discomfort [+ film crew and the considerable back-up probably with helicopters, support ship, containers for equipment etc] that it'll require using the BBC's money just to prove she can... don't say for the adventure. Bah humbug.
If the only justification is that the BBC are doing it to raise money for Sport Relief, just donate the money it would all cost direct? There are a lot of people who go on much simpler adventures to raise money for charity who pay their own way.