Video Broadcast within Retirement Community We would like to send a video/audio stream from an auditorium in our retirement community to a large screen TV in the health center.  They are in the same building but probably 500 feet apart.  There is good wi-fi coverage in both areas. We need something VERY user friendly on the health center (receiving side) of the operation.  Anything more complicated that switching the input on the big screen TV from one HDMI port to another is not going to work.  We have demonstrated the potential of doing it using YouTube Live and with a couple of "baby monitor" apps using an Android TV Box but that is too complicated on the health center side. Any suggestions would be appreciated.
Short of doing a live stream which you've already ruled out, your best bet sounds like it will be a fiber link between the auditorium and the health center.  HD-SDI has a technical limit of around 100 meters, so you would need a booster in between to make use of SDI (which would be a coax run and possibly a bit cheaper).  Neither of these options can be completed for less than a few hundred dollars in cabling alone.

Other than that, your best bet is to provide training on how to use the live stream and possibly setup a device like a roku that can be adjusted remotely over the network by someone in the main auditorium.