Even if you do find a portable DVD player which plays back a DVD upon being powered on, any default input on the TV you use will have to be the DVD input, which might not be possible. I don't see an easy solution anywhere for you that does not involve a computer that has power independent of the building.
I am trying to find a good smaller lcd or another quality tv that has an on/off timer that will automatically play a video either via dvd player or via usb connection.
I am exhibiting video work that needs to be able to power on at the same time each day because the building automatically shuts off the power each night. I need it to play video files automatically without anyone pressing on or off.
Any help on specific brands would be awesome. Any size possible in the price range, small is good. l need to buy three of these so I am hoping to stay under $150 for each.