I have often shot while traveling...I usually don't bring any strobes or anything just because I don't want to lug it around...so, I always have shot during the day on location.
The last time I was in Vegas, I shot a model out at Red Rock...amazing area!!! Unfortunatly, the model was late (big suprise) and we only got off about 20 minutes of shooting before the sun went behind the mountains. It is about a 40 minute drive from the strip...but I recommed it if you have the chance.
As far as getting models, I simply put in a travel notice on the OTHER MODEL PLACE as well as contacting a few models in the area.
Good luck! I will be in Vegas next month around the 23rd-27th...maybe I will see you there!