That's usually a slow week everywhere
The week between Christmas and New Year's is usually slow throughout Nevada. Though I haven't been to Wendover or Mesquite during that particular week, I doubt if they're any different. I'm scheduled to be in Wendover during that week this year, though. Perhaps our paths will cross.
Unless you have a specific reason to go to Mesquite, don't bother. There's not much worthwhile in Mesquite. It's very low-roller, much like Laughlin. Green chips and above stand out. When the casinos are near-empty, the tables are managed full by closing other tables. It is tough to find playable conditions, especially at single deck.
A better alternative to Mesquite is Jackpot, about 125 miles from Wendover. When making plans note that Wendover and Jackpot are the only places in Nevada that are on Mountain time rather than Pacific time.