That is specifically in regards to having mods. You'll need to go completely vanilla in order not to crash for that cutscene.
Honestly, it would be best just to go through this DLC with only the official patch. I experienced a significant amount of crashing, even outside of the Winter Palace, until I removed my mods folder entirely.
I ran into the same problem. A merged mod folder even with no mods at all still caused issues, starting with a CTD at the start of an early cut scene. I had to remove the folder completely, and then of course change the version number in the official package mft to load the save in order to get the scene to play without crashing the game, and solve any other issues. (so far)
Yes, it sucks a bit to play without mods, especially the cosmetic ones you fall in love with, but if you want to experience the DLC, it's a small price to pay.