Depends on the weather. If it's nice out, then everything stays open. If it's cold and/or very windy, then I'll usually pull down all the hatches and just bundle up in my appropriately-rated bag. As evidenced by my platform/fridge configuration, the tailgate must stay down, though.
I will put the tarp up if things look rainy:
(So far so good in moderate wind. I just guy it out real well... the rain is channelled to each side of the truck,
so everything stays surprisingly dry. Not perfect, nor permanent, but I like this setup so far. Was cheap, too!)
Like the sound of this! Please keep us posted as it happens!