One other option if you are dead set on running the wire in the wall and are having problems fishing. This will require a little extra work run the cable into the upper floor using the "closet method". Drill a hole up thru the ceiling as close to the wall as possible (right on the wall line if possible). Fish the wire down into the room outside the wall. Next drill into the wall as close to the ceiling as possible. then cut a groove connecting the holes just big enough for the wire . Next fish the wire down the wall. when you get to the fire break inside the wall come outside the wall again and go back in below the break cutting a groove between the exit and entry points. repeat as needed. This will require small repairs of the grooves all less than 2" x 1/4. if you are careful you can repair this with a little dry wall mud and tape. I don't have any Idea how to handle the horizontal run between floors.
If you have good capentry skills you could remove the baseboard and cut a groove on the back of the baseboard for the cable and reinstall, but that is generally more of a pain than its worth, other options are flat cable , tucking cale between wall and the tack strip if you have wall to wall. Sorry I can't be more helpful.
