The good part of this DLC - story is quite interesting and it's long. It adds some new game mechanics and new locations to visit, along with some old "remastered". For the first time there is a new feature where you can change your shelter and move out with stuff, but unfortunately you cannot carry all of your items, because the transfer capacity is just a backpack capacity of your character, which is sad. Also for the first time you can play and move around like in cinematic mode or movie, but only during some story-related scenes, and in the end (especially when you go for all 4 endings) you see how annoying this is because movement is glitchy and the ladder in the burning museum is hard to be walked through with this movement.
The bad thing about this DLC is everything else - you struggle to survive as the game starts in winter with no basic supplies (except 2 raw foods found around the shelter), you need food and more importantly you need tons of meds to overcome the sickness because of cold, and you need constant suppliment of fuel/tinder, which is hard to get until you craft/buy/find hatchet to chop furniture around you. You have small greenhouse in the basement but that's very time consuming and not worth the result as you play only one character in the beginning. Alternatively you can get fuel by destroying your family art which you were entrusted to keep safe. What's even worse is this DLC is time limit, and about in 25-26 days its game over. So if you are planning to get all of the achievement and you dont want to waste tons of hours while doing so, i recommend you to check on guide on game hub and learn how to extract save file and create save backup when you reach certain day, so when you finish the game and get one ending you can rollback and start right before that specific day and get the other remaining.
P.S. Just like any stories, this DLC doesn't add new stuff to use in the base game. Also there is also logic issue in this story - when you move to the new shelter museum, the old lady goes for the search to find a vehicle and after a few days later you see a cutscene in the morning with her being happy about finding it... and then you see a large truck... Not outside but inside the shelter... In a storage room surrounded nothing but walls and two small doors for people to come in along with shelfes everywhere.... How the hell did she managed to get it there? And even more importantly how the hell you escape with it in the endgame condition when the building is bombed to the point everything is set ablaze and rubbles blocked both exits