This is not really a call for tech support, more like a feedback about a tech issue. Please forward to wherever it belongs.
I have this 120 GB SSD just for ESO, right? The patch is 7GB. Yet for some reason, I run out of disk space while patching - first about 90% in, then after a restart, like
half a GB before the completion.

Great - but I have no more disk space, and I have nothing to delete to make more room, because this disk is just ESO. What to do?
It took me some time to figure it out, but what I eventually did was I replaced all the old *.bik files in the depot/video/ folder with their own empty copies, which gave me just enough extra room to finish patching (thinking about it now, there are probably more elegant solutions possible involving junctions or redirects, but well - hindsight and all that).
So, when the patching is finally complete (some four hours after I started the first attempt), the "PLAY" button pops up, and my disk space counter suddenly jumps from 0 to
36 GB. Really? Isn't that a bit... excessive, a 30+ GB temp to install a 7 GB patch?

I realize it's essentially my fault for not having enough room - but, you know, SSDs are generally quite small, and it would be extremely helpful if there was an option to select a different destination for patch download folder and patch temp folder. That's all.