Rumor has it that Dirty completed it in 5 days. Gunnar immediately goes to the guard post and barely makes it to the city on day 5. Hopefully, we'll see more details soon based on the save files.
I can't manage it even with a "cheesy" approach. With 2000 mana from archangels... AND EVEN WITH GLOVES AND BOOTS, Gunnar can't reach the city on day 1. Maybe I'm going the wrong way?