In my head (as a German), ice tea is almost always store bought like lipton ice tea. You very rarely get anything else anywhere. Restaurants don’t usually serve home made ice tea. It’s a soft drink. When I make myself tea at home, it’s almost always hot. Unsweetened black tea just tastes awful when it’s cold. The hot tea sometimes gets sugar, like when I make myself lemon tea (black tea + lemon juice + sugar), although I do like to use stevia instead of sugar for the same health reasons because I sometimes drink 2-3 pots (1.5l each) a day in winter and that would indeed be a lot of sugar.