I am trying to run a couple of ethernet cables (Cat 5e) to my existing thermostat location in my home in order to install a network enabled thermostat and remote temperature sensors. My home is 2-story stud/drywall construction and I have basement. There is a fire-block (horizontal stud) between the floor and the thermostat location. I know this because I saw it during construction. I have previously replaced the thermostat wire - putting a 6-condutor in place of the original 4-conductor. The hole through the fireblock was barely big enough for the -4, and the -6 was an extremely tight fit. So there is no room to use the existing hole. I could try to go up through the attic, I suppose, but that would be extremely complicated.
My question is, what is the easiest/best/cheapest way to run these wires to the existing thermostat location - past the horizontal stud?