I have a solution, unfortunately, two separate console commands are required.
SetGlobalValue LAX2_n_cpq_01_stage X
0 = quest not started,
1 = received letter,
2 = read letter,
3 = greeted at gate,
4 = sermon interrupted,
5 = dracolich killed,
6 = spoke to cult leader
Choose 5. The town will act as if the dragon is dead. You can progress the quest by talking to Vatnir, but you cannot climb the glacier once you go outside. I'm guessing the cinematic triggers this part of the map. To get past this you'll need to do the following to teleport yourself to the relevant area:
AreaTransition 0b404000-d119-4a60-8924-408f123cbc39 0 0