After several conversations with both the hotel desk and the Hotwire customer support team, I finally have a resolution and wanted to post an update.
The calls with the hotel were, for the most part, not helpful (as expected). My strategy with Hotwire can be condensed down to the following argument: I booked a 5* hotel, and I expect a 5* hotel for my stay. I knew that there were no other 5* properties in the zone I initially booked, so I told them I would be willing to accept a room on the Strip instead.
Eventually I got the right person on the line (or they have sick of fielding my calls) and they agreed to re-book a 5* hotel. They told me they could book me another Hot Rate hotel and gave me three zones to choose from: North Strip - Fashion Show Mall; North Strip - Grand Canal Shoppes; or Center Strip - Fountains. I asked a few basic questions about amenities, and agreed to take the Center Strip property. It ended up being the Vdara. While I would much prefer to stay in the initial property I booked (Red Rock), I'm satisfied with this outcome given the circumstances.
Regarding payment, they effectively transferred my prior payment to the new booking, and provided a credit for the difference, so my out-of-pocket amount is unchanged (aside from differences in resort fees and parking charges). I've included the details for the new booking below:
Star Rating: 5*
City: Las Vegas
Zone: Center Strip - Fountains
Hotel Name: Vdara
Rate Per Night: $221 (before taxes, resort fees, etc.)
Dates of Travel: 4/28/17 - 4/30/17
Date Booked: 3/29/17
Amenities: Condo, Free Internet, Pet friendly, Suite, Boutique hotel, Smoke-free rooms, Fitness center, Pool(s), Restaurant(s), Business center, Internet access, Golf nearby, Kitchenette, Spa services, Accessible for visually impaired, Accessible for hearing impaired, Accessible path of travel, In-room accessibility, Accessible bathroom, Roll-in shower
Thank you very much for all your help on this!