Yes, regular Ortlieb back rollers with some slight modifications to the attachment points to make them more offroad friendly and less rattly.

Glad you asked about the contents as well! My packing list for this trip was roughly as follows;
For camping; a tarp, 2x foam sleeping pad, three-season down sleeping bag, sleeping bag liner and ear plugs
Clothing (on top of what I wore when I rode); clean base layer (for sleeping in), thick wool socks, super-warm expedition-ish down jacket, light down jacket, rain pants, extra wool cap, buff, fleece liner gloves and big campfire mitts to poke around in the fire with
Hygiene; quite extensive first aid kit, toothbrush + paste, towel, toilet paper and hand sanitizer
Food + cooking; 3+1 liters of potable water, two days worth of food, snacks, cooking kit (Primus omnilite ti + two pots & accessories), 0,5 liters of gasoline, lunch box & mug
General items; head torch, extra batteries, powerbank, charger, knife, lighter, fire striker, sports tape, paracord, compass, ultralight backpack, steel wire, multitool
Bike-related; bike multitool (Topeak Alien 2), bike lights, pump, spares for on-road repairs, some extra nuts & bolts and a light wire lock

There was no need to carefully pack anything as there was a royal amount of space in the panniers for that amount of gear.

EDIT: the above pictures sure look nice!