Forgive me for asking, but why would they need antivirus if they have no internet connection? Unless someone is giving them questionable files on cd or dvd?
It sounds like you're storing yourself up a whole heap of trouble. This version updates every 4 hours so unless someone is going to keep going round there and updating it manually (you?), there's not much point, is there?
Still, you've asked the question, but I think that it will be a great deal of hassle for you and for them.
regards, Gizbar.