Disk space

How much disk space will all 4 GW products need in total?

Well my dat file is 3gb and a bit right now. So I'm guessing somewhere between 3.9- 4.9gb.

The complete dat file currently is at approximately 3.5 GB. That very likely already includes a lot of content from EotN, which has been pre-streamed with an update a couple of weeks ago. I do not expect the file to grow very much with EotN going live. Another couple of hundred MB at best, I'd expect the total size to stay well below 4 GB.

They only need to add new skills <1mb, new textures&graphics <100mb, new quests/scripts/weapons/animations <10 mb. So the magic number is 111 mb .

I'd keep up to 5gb free for the .dat file. We don't know what will still be happening in the future, and better safe than sorry.