Yep, already there. The long, linear stuff doesn't make much sense on a stationary house. I've got tons of drawings/ideas (layout, storage, etc.) from all my years of existing in sub-500 sq. ft. spaces.
My current place is 450 sq. ft. and it feels huge/wasted to me, if that gives you any indication about how I'm wired, and see things.
I wouldn't know what to do with myself in 900 sq. ft.!