Furrowing my brow about something I've run into. Got to Didenhil, and when I took the quests to go get the plague cure and kill all the giants in the cave, I asked the dude about "Thaddeus", someone I'd never seen or heard of, and he mentioned that this Thaddeus had the blood plague but was refusing to take the time to rest. Later, when I got back from the quests, I asked the guy again and this time he said Thaddeus had died of exhaustion since he didn't rest. 
 
So I loaded an earlier game, which was significantly "earlier-er" than I would like, and ran over there to see if I could convince the guy to take it easy or something, but there doesn't seem to be an option for that, and I can't seem to find the 'brother' that the questgiver mentioned who'd been trying to get Thaddeus to rest. 
 
So, since all the FAQs that are out at this point are incomplete/crappy, I thought I'd just ask, is there actually a way to prevent this Thaddeus Holn guy from dying, or should I just load my more recent game and continue where I was?

I was having the same "problem" too. I don't know if its preventable.

Fuck Thaddeus. Get bitches.

You can save Thaddeus. First, complete the quest at the Healer's Cottage to give her Plagueshields. This will cure his sister. Then talk to his brother, who is either in their house or out on the docks fishing. After this, go talk to Thaddeus and you'll get a persuasion chat option to have him go rest.

When I did this quest I had already done the Plagueshield quest, but hadn't spoken to anyone else. I had my Persuasion up to, I wanna say around 6 or so, and I got a Persuasion option on that last guy. I passed it and he just disappeared in a puff of smoke. Totally had me thinking when I turned in the quest it would branch into some other shit, but nothing...quest giver was like, "Ok great! Thanks!"