You can definitely use TV on a LAN with no internet. I do it at home and do it at Astrofest every year. I’ll look next time if I remember and post settings.
Be careful using RDP. I recall Chris garbz posting here somewhere that RDP was causing weirdness with some of his Astro software.
Edit: RDP issue -
http://www.iceinspace.com.au/forum/s...&highlight=RDP
Edit 2: googled “team viewer lan only” and the first hit shows how I did it from memory
Edit 3: When connecting via LAN, you use the IP address of the computer on your LAN you're trying to connect to, eg 192.168.0.5 as opposed to the partner ID when connecting via internet