I would say it would depend heavily on the type of iced tea. For example the pre packaged ones such as Lipton iced teas which are flavoured are very high in sugar. Have a look at the nutrition panel. They have just as much sugar as a bottle of coke.
You could try making your own with infusion teabags. There is loads available even at the supermarket. Just make sure it's an infusion, not flavoured. There are fruit and flower based ones. Make up bottles of it in the evening and keep in the fridge. Then you have a cold (almost zero cal) drink.
Highest weight 96kgs
Start weight 93kgs
Goal weight 60kgs