No problem with the plastic bottled iced tea. Instead of packing in suitacases etc, I would have you consider buying the grocery store products in port. You will find grocery stores close to the ship in all ports of call. While you wait for the port, all the iced tea you can drink is FREE on board. We have traveled on board the NCL Star several times with the last being 4 months ago.
I am happy to answer any questions about the NCL Star.