If I'm not mistaken, the Hard Rock pool is heated year round. The Palms probably is also. Hanukah is no special holiday like others like Passover or Rosh Hashana.
It used to be that Vegas was really dead during that period, but everyone now takes advantage of all the deals and goes on there a lot during that time. I know that the highly tipped help used to take that time of the year off since it was so slow. But now in SoCal which is a short 4-5 hour drive away or 1 hour by air, people unwrap the presents and say "LET'S GO TO VEGAS!"