There are a lot of factors to determine if RCI would let you keep your cabin if you didn't pay in full by the final payment date. Including how well the ship is selling and the current economic status. If you just allow the final payment date to pass and do nothing, the accounting dept. of RCI will try to contact you and if unsuccessful, they will just cancel the booking and refund your money in the form it was paid. However, if you contact RCI before the final payment date, you may be able to work out an extension of the final payment date for a week or so, two weeks at the absolute most. That would depend on how that particular ship is selling and how full it is. Either way, you will have to speak to RCI and get the final payment deadline extended, or they will cancel the booking. Good luck, I hope it works out for you.