I'm bringing a Woodland power stove setup for propane fires on the Grand Canyon this spring. My question is how much propane do people find they use with these? I calculate that if we have a 1.5 hour fire at full blast, we'll use 4 lbs of propane per fire. That sounds crazy high, I can't imagine using that much, but I don't know what it takes for those logs to really seem like a nice fire. For those of you that have used these, what you do recommend or what have you seen?