Just an FYI (I know you were talking about PHEV): some people have tried & tested the EV-for-RV route and found it wanting, in the sense that you can rarely plan on driving more than 100 miles at a time despite huge battery systems for the engine. The extra weight really makes a huge difference.
Solar-for-everything-but-the-engine is already a conventional reality unless you need air conditioning, and even that is becoming possible.
Water collection is not a technical problem, but a climate one. West of the 100th meridian, not enough water falls from the sky to collect, most of the year. Even in wetter areas, however, collecting enough water between rainfalls for the needs of even two people is not completely trivial.
Solar-for-everything-but-the-engine is already a conventional reality unless you need air conditioning, and even that is becoming possible.
Water collection is not a technical problem, but a climate one. West of the 100th meridian, not enough water falls from the sky to collect, most of the year. Even in wetter areas, however, collecting enough water between rainfalls for the needs of even two people is not completely trivial.