I wouldnt stress to much about booking place's to stay at that time of the year. On two different trips starting beginning of May, we booked the first night as we had to. After that we just wandered into a place and asked if they had a room. Only once we came undone when we arrived in a small town that had some big event on. We moved on to next town. Only time that happened in a total of 10 weeks travel over two trips. We did also book Las Vegas as the price's there change a lot depending on what's on. Last trip we detoured around looking at other stuff and then came back to get the lower price's. Saved $100 a night at the Flamingo right in the middle of the strip. Searched the price's on line over a couple of weeks that we were going to be in that area.
Keithg