It would be quite difficult to get your membership through in time for your trip if that's what you're hoping for - they are very slow, to the point that the majority of us I think have resorted to emailing just to check that they've received our documents, when I was waiting for mine they had a six week backlog and one of our DISers has had awful problems recently trying to get hers sorted so she could book her hol. Sorry probably not what you wanted to hear.
dh is reluctant to go until either Halloween or Christmas but I need a trip before then !!! I have had a play around with some dates and never seem to strike lucky with the 40% deal ?!! dh also needs a new passport so I have threatened if I find a 40% deal to take dd on my own and dh and ds can stay at home !!!!