You should check with agent to see if prices go down any. If they do maybe you can get a move up for no money. Instead of taking the money back...you could get a better cabin. Or take the money. (If this happends) Chances are slim of getting upgraded from where you are now. Keep in mind you bought an inside and now your in a Outside with little view. If you booked a cat N (Inside) and get upgraded to a cat GG you got a 10 cat upgrade!!! Wow not bad.
Enjoy your cruise!!