I think that the idea of having too many systems is wrong is not always right. In June my wife and I went to Yellowstone and Gran Teton and took Pentax digital and film, a Hasselblad, a 4X5 and a Nikon digital. The Nikon due to having borrowed a long lens that I do not have for the Pentax. But it was not difficult walking about with a tripod and the Hasselblad and having the Pentax digital in the bag for when I needed it (and was able to share lenses with my wife so did not need to carry as many as if I was the only one shooting). And the LF came out for certain shots in an area that I knew I wanted to use it. We were tenting it out of a RAV so less room than most RVs. In your case I think the Bronica and the 645 are too close to the same that you could leave one behind but if you took the digital Canon and the Bronica, how much room does a film body and a few rolls of 135 take? You might have to make some decisions when you start your hike or leaving the RV in the morning but they are not that difficult to make and you will not have the regrets afterwards. In my case I did not use the Pentax film camera that much but I did have a specific purpose in mind and the camera took up about the space of 6 granola bars.