Portables are great, but I prefer to store mine on the roof permanently.
Our single panel (right now) is a whopping 130W. It's been more than adequate for our family of 4-5 over the 18 years we've had it, but we also have a very light electrical footprint.
We rarely run the furnace, and aside from inside LED lights/fridge circuit board while running off propane/phone recharging/~2 hours of TV after dark, we simply don't use a lot of power when on 12V and stationary. That's a conscious choice. Others need more than that due to things like a 110v fridge, CPAP, or inability to live without their Keurig...
It doesn't take a whole lot of direct sun to recharge our lead acid batteries -- usually topped by mid-day. And because our storage space is in mostly full sun, our batteries stay topped off all winter.