Googling only shows me 4 extra bags, for a total of 5:
- Devil’s Crossing, Barnabas: And Not a Drop to Drink
- Arkovian Foothills, Bernard: Clearing the Way
- Homestead, Douglass Sullivan Oldbarrow: Culling the Swarm
- Fort Ikon, Weapon Master Edric: Precious Resources
If there’s a 5th additional bag (so six total), I haven’t been able to find it thus far. Maybe my google fu is weak.