I'm 22 hours into a save, and I've just encountered a persistent CTD in the area starting just north of Anvil and going to about the Brina Cross Inn. I think most interestingly, I had no problems accessing this area earlier in this save, and I only noticed the CTD while doing the "A Rat Problem" Fighter's Guild quest. (I had previously traversed all the area giving me problems before for the "Anvil Recommendation" Mage's Guild quest.) The only mods I've added in progress to this save were some shader mods and Living Economy, neither of which I believe are the issue. Wrye Bash doesn't report anything out of the ordinary, but I haven't bothered cleaning all the little dirty's in the DLC.