You can run an ILDA cable as long as you want but the longer the cable the higher the signal loss as it's an analog signal. More experienced guys can tell you what would be the limit. There are some wireless options but they aren't reliable enough for big events and such.
But there are some DACs that work with ethernet. Right now I can think of the Etherdream and QM2000.net, and Fiesta.net sounds like it works over ethernet too.
And as long as you aren't into big old fancy gas lasers or *really* bright diodes it should run over 220 V
Does it make me a nerd when I go to a party with my laptop?