I'm in South East VA and your border is wrong. It extends mostly up to NOVA, but even in NOVA sweet tea isn't that uncommon.

It entirely depends on what kind of establishment

Either you'll get a sweet iced tea, or they'll ask "sweet or unsweet" before bringing iced tea.

Durham, North Carolina here.

If I asked for just "tea" at a restaurant here in the central valley of California, I would be asked what kind. The choices would be unsweetened ice, sweetened ice, or Lipton Raspberry Brisk (or a knock off brand I always forget the name of that's becoming more common than the Lipton). The only restaurants I know of that Incan get hot tea are Chinese places, and they usually only have oolong tea.

NM here and it depends on the restaurant, many only have iced tea. But when you ask for tea you will be asked if you wanted sweet or unsweetened. If you say sweet, they bring you packets of sugar and a glass of unsweetened tea.

Fast food places will have both dispensers but mostly the sweet is unsweetened.

Southern CA default seems to be unsweetened iced tea, which is basically all I drink so it's fine with me.

In the Texas, you can ask for “half and half” tea. You’ll get a mixture of sweet and unsweet iced tea. In a huge glass with plenty of ice. And free refills.

If you want hot tea, you need to ask for hot tea. Most places will bring you a couple selections of bagged tea and a too-small pot of not-hot-enough water. Hotel restaurants are known for bringing out a huge caddy of various tea bags for you to chose from. If you want milk/cream in your hot tea, you’ll have to ask for it, it’s not assumed.