Carnival's new policy is one bottle of wine per passenger can be brought on at embarkation only. Since a corkscrew could be considered a 'weapon', I wouldn't do that. Ask your cabin steward for a corkscrew. I've done that a couple of times, and have rec'd a Carnival logo corkscrew. Nice little souvenier.
As far as having your anniversary dinner in your cabin - you do know that there's no hot food delivered to the cabins, right? I personally wouldn't want to have sandwiches for an anniversary dinner,
but......congrats, anyway! Hope y'all have a wonderful anniversary cruise.