I have the channels DVR and tv everywhere installed on my server and watch it through Appletv and it works great. Is there away I can use another Appletv and watch my same channels live at our beach house?
Yes, by enabling remote access on your dvr web UI
Great thank you. How secure is it, is it as secure as something like PLEX?
All communications from your app are direct with your home server over a secure connection protected with valid certificates generated for just your server. It doesn’t go through an intermediary cloud server.
One more question, how does the AppleTV from the other house connect to my channels? Do I login somehow?
Yea there is a QR code to login
Is there a limit to how many people can watch? for example could 2 people watch from my house and another 2 watch from the other house?
Depends on your hardware and tuners and bandwidth available at both locations. There is no hard limit otherwise.
I am using remote access this week. We're 902 miles from home and I brought our Fire TV and a lenovo tablet. Both work well and haven't had many issues. I even fired up the VPN so it wouldn't transcode the video and it played just fine.