I pretty much lucked out. I am new to pellet cookers, and I coming from a WSM. With that, 12 hrs is nothing, and I didn't even think about it with the cook last night. I filled the hopper at the start of the cook, and I was up until 2:00 a.m. It would have been nothing for me to top it off before going to bed if could have stopped swaying long enough at that time. In the future, I will make sure I top the hopper off before retiring for the night.