I'm a marathoner and triathlete, and I've NEVER heard of providing people with a meal so you have designated cheerers along the race course. For the NYC marathon, spectator logistics can be tough. I'm sorry, but the whole situation sounds a little SS. But best of luck on your race!!
I must agree with this. I've been both a marathoner and a cheerer. On both sides, finding the other can be a real problem in the NYC Marathon.
A lot can depend on where along the route your friends will be. The further along the route they are, the longer they will have to wait to see the OP and the chances of seeing a friend becomes less likely.
We live quite near 4th Avenue in Brooklyn. That's close to the start of the race so the pack is still pretty dense. When we cheer on friends, we can safely head down when we hear the helicopters. Anyone we want to see will pass in about an hour at most but the sheer number of runners make individuals hard to identify.
Further along the route, things are very different. By the time the race reaches 1st Avenue in Manhattan, the runners can take hours to pass and the crowds of spectators are quite thick. Asking people to wait hours to see one person seems a bit unreasonable even in an stretched-out pack.
Still, good luck in the race.
BTW, do the people invited to cheer and attend your party have an idea of your pace? That also can make a big difference in finding each other.