I think it's pretty clear to say that this is one of the best updates to The Long Dark in a long time. It adds multiple features that seem interesting at first, but also really make sense from a development perspective when you think about them: the As the Dead Sleep challenge and Bleak Inlet region (along with ammunition crafting) provide a huge expansion to the gameplay and extend the playtime quite a lot. I really enjoy that Bleak Inlet and ammunition crafting create a goal you have to work for, which is something that hasn't been in TLD before.
Timberwolves are a good mechanic on paper, but still need a lot of work. They are definitely the weakest point of Errant Pilgrim in my opinion. Not because they're badly designed, but it feels like Hinterland has not done almost any testing on them. Their movement is sloppy and glitchy, they never give up even if you're in a closed place they can't get to, and they can be really annoying at times. Some small things scare them off, some huge things (like firing the rifle and missing) has no effect whatsoever, which is really weird. However, I enjoy that they provide a challenge even for very experienced survivors - I was actually afraid of dying many times, which is something I haven't experienced in TLD (on Stalker and lower difficulties) in a long time. I also like their design - the animation and design team at Hinterland did a fantastic job at making them very cute but incredibly terrifying at the same time. I love it.
Ammunition crafting is very well done. Levelling up the skill is easy, so with good preparation, survivors should be able to craft perfect ammunition in a few days. The puzzle to get to the cannery is also very enjoyable, it requires a lot of planning and exploring before survivors manage to get inside. Bleak Inlet overall is a great region with a lot of unique buildings. I fell in love with it.
Along with these big features, Errant Pilgrim also provides two very important quality of life improvements: breaking campfires and snow shelters. They're something the community has been asking for for a very long time and they're so nice to have in the game. Long-term players will appreciate them especially.
Overall, I really like the update. It's well designed, the features make sense and they're done well. I just really wish Hinterland did more testing, because the update still feels really buggy - especially Timberwolves, as mentioned earlier. My overall rating is 9/10.