That's a pretty usable size, IMO.
My first inclination would be to carve out about 1/3 for "control room" space - or "speaker listening" if you will.
I like about 650 sq ft or so. My room now is 485 and it's tolerable but on the small side.
I like the idea of putting the CR in one of the corners, with the listening position back-to-the-corner, bisecting the right angle there.
That leaves a sort of "L" shaped recording space, which could be pretty nice with minimal finishing.
What's the ambient noise level like? That's a major factor in deciding on wall treatments in the tracking area.
JW