I have the same issue on a fully offline Windows 10 system (1803, somewhat old). R9 390 GPU with 8GB, 16GB main memory, G3900 CPU (slightly below spec but I don't see how that could be the issue).
I've tried Windows 7 compat mode, run as administrator, and turned off antivirus as they suggest on in a Steam thread (for a different issue):
https://steamcommunity.com/app/492720/discussions/0/1750149787519682337/
There is also a steam thread about this issue a while back with no solution:
https://steamcommunity.com/app/492720/discussions/0/2659871632526600811/
It looks like all four of us with the issue have a G series CPU, although not the same CPU or generation and we have all disabled the internal GPU and use an external card (AMD in my case, NVIDIA for everyone else). Possibly somehow related to that?
(As a side note I also noticed looking at steam forums that it is crashing for people on Feb. 29, but setting the date to another day fixes it. Although it isn't the 29th for me quite yet I tried changing the date (before noticing the older steam post) just to make sure it isn't related but it didn't help).
I notice that not long into the loading the mouse stops appearing on the screen. I'm guessing that is when something goes wrong. My GPU's coil whine also increases as that point and watching the task manager it seems to have a brief "not responding" at that point. However, the process stats in task manager and GPU activity in the AMD WattMan still vary some after that both as it is loading and after the bar reaches the end.
I was going to wait until the price came down due to the too rapid (IMO) DLC release that should have been part of the base game but decided to get it (without DLC) after the new refund policy was announced (although I did get the El Prez edition and have the slight bonus content installed if that matters). However, since I have the other five I didn't really think I would need to refund... hopefully there is some way around this issue.