Workaround for apple tv without internet connection?

I live in an area without the possibility of a decent internet connection. I purchased an Apple TV 3 as a test to see if I could stream media from a central location in the house to other TV's using homesharing, and it was partially successful. I have no problem playing music from a central PC to any TV/speaker setup throughout the house. The issue comes with trying to play purchased iTunes movies and shows. From everything I've tried, researched and discussed at length, it appears as though the Apple TV needs an internet connection just to verify DRM even if all devices in the network are authorized and have homesharing enabled.

If there's a workaround for that, please let me know. I've tried everything I can think of, but simply get Authorization Required error from the Apple TV when trying to select a movie, and a connection error when trying to use AirPlay from Windows 10.

I've tried deauthorizing/reauthorizing everything, disabling/enabling homesharing on all devices, resetting all devices, reinstalling all software, etc. to no prevail. It's extremely frustrating that the ATV needs to check DRM against the apple sporadically. I have moved the whole system to my office for troubleshooting. If I connect to the internet initially and then unplug that connection, the ATV will work with homesharing for a while and then quit, so it's not checking for DRM authorization every time.

I hope someone here is much smarter than I, and can provide a workaround for this. If no such workaround exists, my only other option would be to set up a home network using a 56k dial up modem and tying that into my router, although I'm not sure if the ATV authorization would time out before it got a response from the server at that speed. If anyone knows the data transfer required to check authorization from the server and the time required to receive said authorization before the ATV times out, that would be great too. Any help here will likely prevent this from driving me full bore insane.