One Room Or The Whole House
The question that actually settles it is where your floor can stop without looking as though it ran out. A doorway is a clean place to stop. So is a step, a change of level, or the line where an open room gives way to a hallway. Stopping in the middle of a space you use as one space is what reads as unfinished, and no color choice rescues that. When we walk your rooms we point the stop lines out as we go, and you will find you can see them for yourself immediately afterward.
Working in stages is perfectly sensible and it is worth setting up properly at the start. If you know a second phase is coming we record the exact color and finish so the next run matches rather than nearly matches, and we place the first edge where that second stage will meet it. Your floor then reads as one decision taken twice instead of as two separate jobs. You keep control of the pace, and nothing about the later rooms gets harder because you waited a while. Room by room or all at once, what goes down does not change: here is the layer by layer specification.
