Looking to buy a drop bag for my NRS Otter 140. There is 13" from the top of my floor to the top of the frame and ruffly 43" inside the tubes. Although a staff member at NRS said there should be 45" inside the tubes. The drop bag will be used under a NRS campsite counter to hold gear, not to hold a cooler/dry box. Are the drop bags adjustable in depth by an inch or two? Right now I am looking at the DRE 44" x 18" x 9", and the AAA 44" x 19" x 11".