WOW!!! there's been some.... errr... interesting answers made up from thin air so far!!!
Technically it could work.
You'd need a freeview box with an output that matches one of the inputs on the projector and you'd need an antenna to pick up the signal, the two most likely options for this would be
1) scart on the freeview box and composite on the projector (with correct leads/adaptors)
2) HDMI
You'd also need a suitable TV aerial, depending on how far away from the transmitter and local ground relief this could be anything between a small indoor type aerial, or a hi-gain aerial on top of a flaming great big pole.
So it could be possible, but if you're asking the question you won't be able to do it by tomorrow.
Just take them all to a local pub to watch it!