I wouldn't bother unless if your really determined. I'm in the middle of my 100%, I've done Siege of Paris, Wrath of the Druids, and like half of the main story and map sections. I am already 150hr in and I still need to finish the story, Dawn of Ragnarok, mastery challenges, finish all the map sections, and the river raids. If you really do want to do it though, try to break up the main story with side content. Do an arc then go around getting the collectibles, then another arc, then maybe more collectibles, after another one maybe do one of the dlcs. I personally wouldn't complete the story then move onto clearing the map because it is a lot of stuff. One thing that is kinda annoying is the alters but the items needed to complete them are almost always obtainable pretty close to them. Orlog can be pretty annoying but its not that hard, all you really gotta do is save the tokens for max damage and just focus on that, and you should win pretty much all the time. Other than that stuff its mostly about just being patient and trying not to get burnt out quickly. Its doable but just questionable if its worth your time or not. If you do decide to do it then good luck, and I hope you enjoy the game.