Hotels in Vegas do sell out especially when there is a convention or a big event in town. For your dates I think it's unlikely, since you're not staying over a weekend and you're visiting at the hottest time of year.

While Las Vegas has over 150,000 hotel rooms, the city frequently reaches 100% occupancy during major city-wide events, holidays, and conventions. In 2026, "sell-out" dates are common during New Year's Eve, the Super Bowl (when hosted in the city), and massive trade shows like CES (Consumer Electronics Show) in January, which attracts nearly 200,000 attendees. During these times, even "budget" hotels like The Strat or Excalibur can see room rates spike to ten times their normal price, and finding a "walk-in" room is virtually impossible. Additionally, the emergence of the "Sphere" and the Las Vegas Grand Prix (F1) has created new "peak weekends" where the entire Strip reaches capacity. However, during the blistering heat of mid-week July or August, or in the "dead period" between Thanksgiving and mid-December, occupancy can drop significantly, allowing for the "room upgrade" and "comp" offers for which the city is famous. It is highly recommended to book at least 3–6 months in advance if your visit aligns with any major concert residency or professional sporting event.