You need to put the antenna where the signal is strongest at your location, not where you would like it to be. There will be hot and cold spots for the signal; it's trial-and-error to find the hot spot. The signal is not uniform because it is scattered by the terrain obstructions on its way to your antenna.
The extra length of coax will not matter IF a GOOD preamp is close to the antenna.
You have tried to make too many compromises in your antenna system that will reduce its performance. I can't guarantee that you will receive Fox if you follow our suggestions, but it will improve your chances.
To review:
1. Use a UHF antenna that has good gain on channel 27.
2. Add a good preamp close to the antenna.
3. Mount it outside in the best location for Fox.
4. Aim it at Fox and do a channel scan.
5. Connect the output of the power inserter to just one TV at first before adding a splitter.