(Edited to add: I obviously missed the prior post by Bobmann indicating that he had found FF seats.

I'll learn to read one of these days.)
Several carriers (at least US and NW) are showing fares of $195 + taxes for NYC-LAS for that weekend, on Travelocity. That might be a better deal than spending 25k miles and flying to a different airport. Those fares may require a 14 day advance purchase.
Yes, it is frustrating to hold miles for a trip and then not be able to find availability.