It's a bit of an easter egg/secret. So the ice-woman you get it from mentions how she was partially created it with. What other type of creature/character from American culture has been miraculously given life while being made out of snow? Frosty the Snowman. In Novos, in the area where the witch's house is, down by the bottom right of the map area there is a snowman. Go up to the snowman and click on it. You'll be prompted to add the Eternal Snow to it. You'll turn the snowman alive and proceed to have a secret boss-battle with it.
The endgame has pretty much been finished for awhile now. The one thing that has primarily changed, endgame related, were the numerous bugs regarding the end credit slides that didn't properly show your player character's choice. (Looking at you Emek's Rest DLC). Last version Meredith's slide didn't even show up for me. Essentially what I'm getting at is that the main/ base game has been completed. What these "little" patches are more for flavor, adding new cosmetics, new characters, new quests, etc... The devs also use these patches to go back an add onto or create new companion quests like Galhart's quest last version. Note the devs are still planning on doing one last companion quest for Carys and Seren that hasn't been implemented. The only relatively unique and substantial thing they added recently was the Whitemoon Abyss. Where it's a dungeon slog of boss monsters without cheats. I put little in quotation marks earlier because the devs do make DLC patches. These patches are not little. Like Vesunna, Emek's Rest, and Vesper's Booty. Those DLCs are much larger and have more unique mechanics/encounters. The next DLC will focus on the Tilanese homeland in the north of the world map. Those DLC patches I usually encourage others to play.
If you just want to experience the sex scenes: There's always the gallery mod that isn't complete, but it does usually show the new events. You can always go the hidden pictures folder in the game files, and sort by new, to see the new sex scenes added to the game. (Without the text though).
If you want there is an efficient way to play through the game and experience new content though. So if that's the case, I'll give you my recommendation as someone that has played this game for years. Have two save files from after the devs introduce the new starting area quests. (This was some versions ago). The reason I state this is because the only time sensitive, miscellaneous quests, happen within Oakshire. Main quests are time sensitive, but the random miscellaneous stuff is not. Thus it doesn't really matter what time frame you're in to complete a miscellaneous/sidequest/DLC. As long as you're not in the endgame quest. So have a male and female save file. And pick whichever origins you like most. And playthrough the game with them, as good morality/high affection all characters/all companions and castle NPCs/all castle upgrades, and save before the end in ACT III. (If you want to make it easy on yourself you can always use the skip combat cheat or the Dragon Sword to breeze through combat. Do all companion/side/miscellaneous quests that you can, get as many of the current sex scenes that you want, and keep as many people alive, and happy with you, as possible. The one exception to this is you need to enslave Xyless. If you have her free than complications arise. If you have any previous saves that follow my outline above you can use those too. Or if you get any saves from others.
I'd complete as much as possible because it will be easier to locate the new quests with everything else done. If you have the two saves as I mentioned. Make a folder on your computer and add those saves. Carry over those saves when there is a new update and you want to experience the new content. You'll be limited by the two origins, however this setup will maximize the amount of new content you can efficiently play. Being in ACT III right before the endgame, with your two favorite origins, two different genders, with all companions/castle NPCs, and all upgrades, you'll be able to go back in the game locations and do any of the new quests/events as they show up. Because as I mentioned before the miscellaneous stuff, and DLC, are not time sensitive. Only the Oakshire quests, for obvious reasons after ACT I, and the main quests are time sensitive. (And the main quest is already completed). With the way the devs make these little patch updates there is always new content for both genders regardless of origin. Sometimes there is new content for a specific origin, which you can't always experience, because of the two save files and five origins. Which is why I recommended to pick your favorite two origins.
I hope that helps explain things for you. It's a lot to take in all at once. But since your writing had perplexed undertones. I wanted to help you out by explaining things as best I could. At the end of the day if it's not worth it to you, you don't have to play the game anymore, it seems you got most of the story already. Besides re-downloading 3-4gb per game version can suck depending on your internet.