Seven years ago I had a setup that worked over about a sixty foot length of wire.

It was one pair of a CAT5, connected using no balun or other matching device, fed from a plain old video camera that I had rescued from a restaurant that was going out of business. The camera had a mic on it, so I hooked that to another pair and got audio without any hum whatsoever. I used the other two pairs for power. It was intended to be a cheap and dirty way to see a space and it worked way better than I had any reason to expect.

Try it! You might have to go to CAT6, but it might be no more difficult than that. If it doesn't work, heck, it's already Wednesday.