In the South East, they bring you sweetened (usually far too sweetened for my tastes) iced tea. This is amazingly universal.
I live in NC and have been probing the border for years.
For “nicer” restaurants, the universal sweet tea boundary seems to be precisely at the NC/VA border.
NJ here. If you ask for just “tea,” it usually means hot tea. You’ll then be asked for the usual add-ons, milk, lemon, so on. It’s usually black tea, some places will have others, and they’ll ask if you just ask for tea. Unless you say “iced,” “unsweet”, “sweet”, or any flavors they might have, they’ll usually assume hot tea.