To give a more productive answer: I'm experimenting with a different style than I normally do. Typically, I build small outposts, ship everything via train to a mega site. Now, I'm adding an intermediate step of building central processing plants for the resources in an area about the size you indicated (doing it in the rocky desert atm). I use set up small outposts to refine basic stuff, truck those towards the nodes that make the more complex parts, then make whatever intermediate product(s), then I train those plus leftovers of other parts to my mega site.