Thorough, practical, real world experiences relying on various phones for navigation, communication, photos, journaling and entertainment would, indeed, make a series of great articles.
Confirming the battery issues but I think they are more complicated. My iPhone 4s in GPS mode, running MapMyRide, takes the battery from 100% to under 40% in less than four hours, much more quickly below 45F. A good day of touring can be eight to twelve hours between overnights so the phone will be dead long before camp is reached.
The expense and mass of auxiliary battery packs are not trivial. You need at least two aux battery packs, one hooked to the phone and one to charge the phone at the end of the day's ride. But two packs are not really adequate; you need three battery units: one to run the phone on the bike, one to recharge the phone at night and one that is either topped off or that is being recharged by mains or solar either on the bike or in camp. If you have only two packs, you cannot safely assume you will be able to recharge the other one so, when you get into camp, you can easily have two depleted battery packs.
Solar is not yet viable if you depend on your phone for everything, just do the math. A panel that can fully recharge a pack of 4-AAs or a li-ion pack while riding is both big and heavy. And solar is not magical. The panel requires lots of direct sunlight to do its job.
A bike-powered generator would be my recommendation but I don't like the idea of a power hub. I have no experience with bike generators yet.
My Goal Zero Guide+10 battery pack (4-AAs, heavy duty case, circuitry and LED lamp) is seven ounces. CArrying three of those, plus the big Goal Zero #7 panel, is more than two pounds. My experiments are conducted just riding around the valley but I can tell you it's a hassle to keep the batts in proper rotation and the solar panel fully exposed on the bike. My recumbent has more places to rig the panel than conventional bikes but the thing is not small and, no matter where I put it, it's always in the way. Also, even in Idaho, insolation simply is not reliable as a power source.