Howdy,
I doubt the Confederates could continue to support an army upwards of 12,000 in Northern Arkansas by this time either. Like most of the South, Northern Arkansas had been stripped of most of its resources and food supplies.
That being the case, the Confederates had to do something. They could not simply remain in camp in an area that could not substain them.
Whether it be a raid or an expedition, during Price's incursion into Missouri he confiscated numerous wagons and supplies. So many wagons in fact that they contributed to his defeat at Mine Creek because he was unable to get them across in a timely manner. Most of the wagons and supplies ended up being burned or simply abandoned during the retreat.
Bobby