The base download is about 60GB. When you unlock DLC you don't have to do new downloads. However every update of the game is also a large download (but not 60GB!). Add on top of that the bandwidth used by playing.

If you in a technologically backward country that still has slow capped internet you might want to go somewhere and download it instead. What I don't know and I've never seen clarified by Zenimax is whether you can simply zip the directory up on one machine and unzip it in the same place on another and snail mail it via USB stick.