One other location you might consider is see if a local church will let you use their fellowship hall. If any of your officers are active in their church, that may make it even easier to get approval.
Many churches are very willing to allow the use of their space for little or no cost. If somebody is looking for a church home, visiting for the school function may prompt them to return to visit for a worship service. While the #1 way to get a guest into church remains for them to be invited by an existing member, the #2 way is to get them into the building for some other reason during the week.
How about family night at your local high school basketball game?
Sometimes older siblings are playing and that's pretty cool.
Our school gets the upper balcony at the local high school basketball games. The kids don't mind the seats and the high school team LOVES a packed house.
Depending on where you live, perhaps you can do something outdoors. Or wait till spring and have a big outdoor party/carnival with bounce house, etc. Have the dads bring their grills and make hot dogs, have moms bring cupcakes and have a cake walk. Rent a popcorn machine and helium machine. Better yet, have them donated. Go to car dealerships. Lots of them have stuff like that.
NVolved, I can tell you that the cub scouts reserve our elementary school gym frequently for pack meetings, and basketball teams reserve it as well for practices. They just fill out a building usage form. School events always come first, but if the gym is available, it is open to community related activities. One more suggestion. We used to have a family night years back where we would reserve the high school swimming pool. I don't know the particulars, but it is another idea.
