A few things here - 1) TFA is referencing household use, and you're referencing individual use, and 2) the linked source from TFA doesn't actually give the 1135L/day stat. What it gives is this: "Each American uses an average of 82 gallons of water a day at home" which is ~310 liters.
Also, it's not clear if your source is including water use for home irrigation and recreation (lawns and pools?), whereas the US source is.
I don't think the distinction between indoors or outdoors usage is relevant, in the end we are still talking about the volume of drinkable water people use. Whether they use it for drinking, cooking, washing, or watering the lawn.
Also, it's not clear if your source is including water use for home irrigation and recreation (lawns and pools?), whereas the US source is.