Agreed. I can bank my stove and get decent heat out of it for about 2-3 hrs. I will pile rocks under and around it and heat those for several hours while I am cooking, etc. Doing that will extend my night-time heat by a couple more hours. From then on, it’s all about the sleeping bag and other insulation layers.I think expecting one of these stoves to keep the tent warm for hours on end, is not realistic, nor what they're really designed for. You should have a sleeping bag rated to what the outside temp is and expect it to be that cold most of the night. The stove is to warm up when you return from hunting and to dry stuff off in the evening (with continual attention). I'm new to mine, but even with hardwood, I don't imagine I could keep mine really heating on its own for more than a few hours, when loaded up.