From what I understand, the snow actually can form something of an insulation over the grass. However, I would say that the grass will be fine, we deal with sub-freezing temps every year in NC and with little adverse affects. You may have some winter kill on the turf, but that isn't a big deal. Just make sure the players are aware of the fact that the course may not be in 100% shape come mid-spring. But overall, it doesn't do that much damage to the grass to have freezing temps, I would imagine courses in LA have roughly the same grass we have in NC.