I'm about to be posting the update here in about 5 minutes, then I will begin typing the changelog :D
The demonic whirlpool is safe to go through, there is just no way back until you progress the main questline, everything there is pretty side questy but major upgrades and you should definetely talk to all the NPCs in the City there! :)
The quest completes actually when you walk into that broken igloo! Haha so I'm going to be hopefully fixing that with this update im about to be posting :)