This is a great addition to any artic campaign, the new Icewind Dale hardcover adventure, Season 10 of Adventurers League, or the Oracle of War storyline in Eberron! The encounter tables alone are worth the price for the PDF, plus they are split between In Town and Wilderness encounters so if you are running the Icewind Dale hardcover you won't accidentally TPK your low level party early on, plus those In Town encounters will still be entertaining and fun for mid and late game.
The addition of two whole adventures, one for Icewind Dale and one for Eberron, both are Tier 2. The Icewind Dale one nicely connects the hardcover storyline and the module storyline or can be run separately in either. This is especially nice since, as written, the hardcover is a bit light on magic items and consumables by the module included here has several of each! The Eberron adventure lets the players explore more of the fantastic setting that is Eberron and has some interesting Legacy Events that I am curious to see how they tie in to the ongoing plot!
There are also pages of DM resources. Want some random environmental hazards? Local flora and fauna that can be beneficial? Need some fun artic themed diseases/afflictions? New artic magic items and spells? New monsters and NPC's? All of that is included! A literal treasure trove of DM resources that you don't even have to fight a white dragon for!
Finally, there are 10, yes 1-0, new subclasses! All are super flavourful and well balanced.
Yes the subclasses, magic items, and spells are not available in Adventurers League play without campaign documentation but EVERYTHING else is! Plus all the content would make a great addition to any home campaign.
TLDR: This document is DEFINITELY worth it to purchase!