NON REVING?
As a retired US Airways customer service employee (36 years), I have some experience with the holidays. It can be done but I wouldn't recommend it! Loads are always heaviest! Christmas eve and New Years eve typically offer the best chance as everyone gets to their destinations early! Especially New Years eve.
If you go, thoroughly investigate ALL options. I would really recommend considering LAX. Not too fare to drive and many more options than PSP! I remember mostly smaller jets and props flying into PSP! Have back up passes for travel on other airlines avail.
If you can afford it and you need to go; consider buying tickets. I realize that counters using the free passes! Best of luck!
Ray