I would take my lightly loaded leopard on any river wide enough to navigate. Of course its all relative to how much gear you wanna run. The tube diam of 26.5" gives you a lot of flat surface area --- even if loaded it doesnt draft maybe more than 8". Strip off the four passengers and their gear i would think more like 4"? I've seen others run an Ik under the frame too for more buoyancy
Hey, if you want me to take a dump in a box and mark it "guaranteed", I will. I got spare time.