We are due to arrive in less than a week, and are rethinking the regular DDP, thinking perhaps we would prefer DxDDP, but I do not want to commit until I am sure I can get add'l ADRs. Can we upgrade from DDP to DxDDP when we checkin, or must it be done in advance?
I'm not sure, but I think it has to be done at least 48 hrs in advance. My advice would be to get on the website and make your ADRs and then call in the a.m. You can always cancel the ADRs later if you can't upgrade.