Switching Cabins with 'Drinks on Us' and Onboard Credit

[ilangal]

I need your help...I did some research but did not find this exact scenario. I know that I can switch rooms once onboard, but here is the situation. My best friend and I both received Carnival Players Club offers. Each offers the 'free drinks on us' but hers also offers a significant onboard credit (mine very minimal). Her onboard credit must be split between two persons in the cabin and she is okay with me getting the credit. My son and 5 year old grandson are also traveling, but my son did not get the discount/offer.  So, I want to book my son and I in one cabin so he gets the discount and  my friend and my grandson in the other cabin. When we get on the ship, I want to switch rooms so that my friend and I are in the same cabin and my son and grandson are in the other. Will the 'drinks on us' follow me? Or, is it assigned to the 'player' and not the room? Once the swap is made, will I get half my friend's higher on-board credit or will it follow my grandson? Also, what will happen to my smaller on-board credit? I am okay if my son or grandson get it. Bottom line: How can I get the best of both worlds..........the 'drinks on us' and the higher onboard credit?