How about a 'first in, last out' protest? Go in the minute the gates are open and leave when we are removed.
A couple of thousand people singing in an empty ground would make a fair amount of noise and the message will be simple 'We were here before you came and we will be still here when youve gone!'. The press will be in the ground to cover it and we could easily congregate in the same area. Also means everyone will be up for the game and ready to do the most important thing, supporting Newcastle United.