Jmacn, the data we all link to is from a number of trips in the Grand Canyon using this tool: Solar Pathfinder - Solar site analysis
I got to log in a few of those on an early 1990's GCMRC science trip. It was certainly not an exact science, as it depended where the pathfinder was set up on the beach at the camp or location we were at. It would take multiple trips or many units to get better coverage for additional camp sites.
That said, winter sun is good at Nanko, Kwagunt, Tanner to Cardenas to Rattlesnake, Parkins, Bass, Below Fossil, Galloway, Stone, Stairway, Whitmore, Parashant, 202, 209, Pumpkin Spring, 220 upper and middle, 222, 224, and 242. Hope this helps, yours, tom