Not sure what you mean by preparing your list in advance, but I'm sure you'll all have your own style of organizing and performing the method. You'll definitely streamline a lot of stuff early on.
As for iwgp, or any drama, you can basically find and stream anything released after 2000 because it was most likely fansubbed and archived on one of the thousands of stream sites. I'm not advocating using any illegal site, but some of those shows are even completely on youtube so I don't really know what the internet view on that stuff is anymore. Like, if youtube has it, does it matter if you use some giant drama streaming site? Illegal is illegal, but if the content owners haven't gone after the youtube version..
Anyway what I'm saying is you can watch iwgp like right this second I think (I haven't tried those sites, but they're usually attached to k/c drama sites).
As for subtitles, I'd run into this problem randomly if I found something I wanted to watch (in whatever language) and it had hardcoded subs. I'd just open like notepad or some small window and put it over the bottom of the screen. When I did listening practice back in the day and I had some random fansubbed show, I'd put like a piece of paper on the bottom of my computer screen. Nowadays, at least for new stuff, you can easily get raw copies. There are dedicated people, again on youtube, who rip directly from tv and upload like every weekly show.
Edit: see what I mean, I just typed in iwgp in youtube:
https://www.youtube.com/watch?v=UP1TIl4OyXA
Sure, it's shit fansub late generation quality, but it's there, ready to go. Cover the subtitles and you're good to go. So maybe you can find a better quality if that matters to you, shrug.