Have there been any reliable estimates regarding the crowd’s size?
Sorry, the crowd estimates were from various news reports. If you don’t believe them, then I can’ty find any other source for these numbers. The estimates are from 80,000 to 100,000 for what it’s worth.
Unfortunately, no. The only estimates are from Trump partisans or people inclined to like Trump (like the Wildwood City Councilor who was at the rally). Elsewhere, people have contrasted what a rally of that size looks like (Obama in St. Louis in 2008), and concluded that Trump's is nowhere near that, per the post below:
https://twitter.com/cturnbull1968/status/1789650810495799556?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1789650810495799556%7Ctwgr%5E1dbd845156a085b1bd097fdde34073a92a4fcb1f%7Ctwcon%5Es1_&ref_url=https%3A%2F%2Fwww.newsweek.com%2Fdonald-trump-crowd-size-questions-1899634
State Police estimated 80 to 100,000