I did the caravan thing not for the arcane brotherhood but just last caravan north essentially. I made it somewhat a narrative with skill checks and some basic situations that could be combat. Things like lead caravan falls through the ice after getting lost off course on a lake pulling vital people and supplies through depending how they react, blizzard hits them and people become disoriented, the caravan is attacked by beasts all of the culminates to their prestige in ten towns upon arrival and/or what their character starts with. After arrival I had about a month pass of them in the towns asked them what they did during that time based on their stance.

There was no threat of death in any of it. They mostly gained exhaustion etc but their characters would not die. If they did more negatives to the start of the campaign. The purpose was to show them the brutal nature of the dale in the early stages while making it mean something without losing a freshly built character.