I don’t see why not. Basic americano has one portion of espresso ( which is ok ) and a lot of water. If you add sugar of milk, then obviously you will break the fast. Other than that - should be totally ok.
When summer hit, I made my regular coffee, then put it in a glass jar and kept it in the fridge until it was cold… Just watch out how many you drink because you can chug down cold drinks far faster than hot ones, and may end up drinking 5-6 just to stay cool!!! :)