Yeah, it is pretty weird...I have a rx580 and it runs normal and cool, my buddies that I play with have 1080 and a 5700xt and both their cards are running hot in the mistlands. Seems to be a bit better once you get the wisp light, so I am guessing the fog is causing it, at least in their case. If you haven't, I would look into setting a custom fan curve on your gpu...but I am guessing if it sounds like a vacuum cleaner the fans are probably close to maxed already.