Have you considered flying into an alternate airport? (like LAX?)

Yes, it is a 4 hour drive, but consider this: If you can get a non-stop, NYC-LAX, that will probably cut out 2 hours flying travel time versus if you had to make a connection in order to get to Las Vegas. (For example, EWR-IAH-LAS or EWR-ORD-LAS, etc - the layover plus flying out of the way is probably around 2 hours extra). That would make flying into Los Angeles only about 2 hours longer in total travel time versus going to Las Vegas.

Another thing that you could look into is an open jaw award ticket. I flew east coast to Phoenix and then returned Las Vegas back to east coast. I then rented a car one-way and got to see Phoenix, Scottsdale, Sedona, Grand Canyon, Hoover Dam, and Las Vegas.