I thought about portable panels and purchased 2 100 watt panels and a cheaper PWN controller to use as portable. Well like already posted it didn't take long to tire of dealing with the panels so I threw them on the roof and haven't looked back.
Your camping style sounds a lot like mine and I find even in partial shade I get enough sun to keep my batteries up with my minimal use. The only time I find I need more is during a 2 week hunting camp stay where it's under 30 degrees and I'm running the heater. Most the time the solar does fine even with the heater use unless it's cloudy and snowing.
My advice would be to put 200 to 300 watts on the roof with a PNW controller that has some room to add a panel or two and try it out. If you find you have enough then good deal, if you find you need more then you can add more panels on the roof or maybe decide you need 100 or 200 watts worth of portable for them really shady spots.