Alright here's a long answer that covers possibly using your bathroom windows for your antenna location, and, if that fails, your roof.

As silly as it may look, those 12x48 inch windows in the bathroom may just be able to do the trick for you -- especially if they have a clear view to the south (if the sight-line from the window is not blocked by other buildings). It's worth experimenting with:

1. Bring one of your televisions into that bathroom (to narrow down the possibility of a bad long run of coaxial being the problem)
2. Put an antenna like the Winegard Flatwave FL-5000 or even your cheap Amazon antenna on the window.
3. Directly connect the coax from the antenna into your TV and run your TV's "scan channels" feature for 'antenna' or 'air'

If that process gets you all the channels you want, then you can hide the antenna with a little window curtain from Home Depot. Return the TV to its normal spot and consider using a preamp like the RCA preamp 1 to lock in the signal you receive before the long-run of coaxial to the main TV room. Buy some coaxial cable to run from the antenna in the bathroom window to your TV, and use some special coaxial staples to keep the wire hidden against the wall.