Do yourself a favor and rent a floor sander for like $80 bucks a day and save your orbital sander for the edges next time. That or duct tape the orbital sander to a stick.
I helped my parents sand their log walls just before Christmas. After we stain and seal the logs, they want to tear up their ugly grey carpet and install hardwood floors. The argument now is how dark they want the floors to be. Yours looks so good! I'm sending them your picture for reference. (They have Wheaten Terriers)
Yeah we wanted dark floors, medium walls and light ceiling. The walls in the picture are unfinished but now we have them stained a medium orange/brown colour.
Bonus pic with couch back in place and walls finished:
Those floors hit hard. I wanna do similar to mine, rip out all the white (why white?!) carpet out of the bed rooms and bathrooms (why would you do that?! Yuck!) And just go hardwood like that.