I’m in the same boat. I submitted a bug report before discovering this thread. I have attempted the quest 3 times, the first two resulted in getting stuck at the “Kill the Sons of Svanir” portion after releasing the minotaurs. I killed all of the hostile Sons, but two remained non-hostile “green” NPCs and the quest no longer progressed. On the third try, it got stuck at the “Get the Sons of Svanir drunk with ale from the cart” portion, when those two NPCs still remained and did not progress to the part where you open the gate.
Discovering this thread was painfully disappointing. Thus far, on all other characters, my experience has been great. Not sure how it can be taking so long to resolve this.