For what its worth, I booked several tickets out of EWR to LAS during this time period, three of them on the 5th. We bought FC tickets to ensure upgrades and are we happy we did. Not only was availability in F low, but CO seems to have removed one flight on the 5th (two on the 2nd, the day I'm flying). Also, with EQ changes, I receall seeing a six row FC being replaced by a 3 row FC. Things got so bad that on our return (10th) with 5 of us upfront, when they did an EQ change, we lost the FC seats we had confirmed. Luckily, I caught this early enough to snag five FC seats on an earlier flight. I don't know what gives here, but this must be one of the most busy weeks Vegas sees and CO is cutting back inventory. I wouldn't count on an upgrade based on what I experienced. Good luck.