That's a great picture.
I agree with the backpacker philosophy.
We used to hump an old tent that was basically the big, ole "cabana" off a 1970s VW Westfalia. We started using a MEC 2.5 person tent for me, the spousal unit and the dog. Works great and I have all my cargo space back with some to spare (LWB). Once my little guy gets to be about 2 or so we'll start at it again in a big way. Might have to get a slightly larger tent if the dog is still around.
Another thing to think about
: food. Pack backpacking style food too. We got away from keeping bulky stuff like beer and and fresh meat chilled in a big cooler. It just isn't space efficient.
A flask of "good stuff" with some orange crystals is good enough for a few drinks around the fire in the evening. I found that once you got past 30 years old, waking up hung over in a sleeping bag and then wheeling all day really was too hard on your system. I tend to drink stuff straight these days.
For food, mostly everything is packed dry and is very small to pack. We will keep fresh meat type stuff for the first night in a collapsible cooler bag. It gets used the first night so you aren't humping it around everywhere after that. Have a look at some backpacking cook books. It is amazing the kind of meals you can have cooking that way. My wife is a genius when it comes to this stuff...
The next big bulky thing is water. Not much you can do about that until you can find a solution to the recursive problem of powdered water crystals.
Spares is spares. I want to make some between the frame rails compartments for packing axle shafts and such.
Just my experience.