The reservation is still available.
As far as whether or not it is big enough for you, that is a decision that you need to make. Listed below is the square footage of the room, along with some comparisons to other Disney accommodations. It will be set up with a Queen size bed (high off the ground), a fold out sleeper couch with a couple of square coffee tables, along with a small table and 2 chairs. 2 Additional chairs will be on the verandah, and pictures are available on the disboards if you look. It will have a small counter with a refrigerator, 2nd sink and toaster, along with some paper plates, etc.
AKV Kidani - 366 square feet
Jambo - 365 square feet
Value - 316
BCV - 365
BLT - 329
BWV - 359
OKW - 390
SSR - 344
VWL - 356
From a comparison standpoint, a
Pop Century Room would be 260 square feet
Category 11 cabin on the Disney Magic is 184 square feet
Catergory 4 family suite on the Disney Magic is 304 square feet.
As far as adding another night, I don't have the points, nor are there rooms available through
DVC. Disney is of course happy to rent a different room to you (Animal Kingdom Lodge standard view would be $400 plus tax for Dec 18th) and will assist with transferring luggage between resorts through bell services (tip is expected). I will go ahead and PM you my email address if you have any other questions.