I don't know if it is possible for the charity event, but if you could send it to 2 displays, it might cause fewer sore necks from those with their backs to the TV. Assume you might have some less experienced players at a charity event, so it is useful to have those blinds available for everyone to see easily. May simply not be possible with the resources you have. And it certainly isn't necessary.
I don't know if you can send a laptop display out to 2 different TVs. I mean, there must be way, but I don't know how to do it.
For my 20 person tourneys I try to use 3 monitors so that no one has their back to a monitor and most importantly so that the 2 dealers can both see the monitors easily. It works well, but I wish that my cabling was a bit more clean (3 cables are going all over the place, but I try to route them along the walls for the most part).
Plus I have to put the monitors on rather tall stands so that everyone can see them over everybody else's heads. I use our computer flat panel monitors (we have a couple 21-inchers and one 19 incher), so I don't feel like having wall brackets and then having to disassemble the monitors to attach them to wall brackets, so I just throw them up on some stands I made that are about 4.5 feet tall.
I would say that it is overkill, except that everyone is always referring to them (I think they have gotten a bit dependant on them and never try to remember what the blinds are - but we often have less experienced players).