And it is even more than that.
As I have frequently mentioned, Miami is built upon limestone. The uppermost layer is approximately 15 meters thick and known as the Miami Limestone. That layer was deposited during the Sangamon Interglacial. That is the last interglacial, and the one between the Wisconsinan Glaciation (the last glacial cycle) and the Illinoian Glaciation (the glacial cycle before last).
Now I invite everybody to ponder that for a moment. A limestone bed 15 meters thick, deposited under Miami during the last interglacial. That alone damned near screams how cold this one actually is, as sea levels are nowhere near high enough to completely submerge Miami and allow coral reefs to grow there today.
And below the Miami Limestone layer we have the Fort Thompson Formation. That was formed during the Aveley Interglacial, some 250 kya. Now that is a layer that is around 3 meters thick.
And below that is the Tamiami Formation. And the problem going back beyond that starts to become compression, as when you go deeper it becomes increasingly harder to differentiate the differences between one and the other. As that all generally blends into the Hawthorn Group, which dates back to before the current ice age even began. But I just named three distinct layers that predate the current surface. Going back close a a million years, in an ice age cycle that has been ongoing for over 3 million years.
You listed out one of the hardest to find sources of evidence, as very little of previous glacial cycles exist past the most recent one. One thing about glacial cycles, they are damned good at erasing any evidence of previous cycles unless it extends past the limit of the most recent glaciation(s).
Until the first part of the 20th century, most geologists only recognized a single glaciation. It was only in the 1920s that it became accepted that there was ample evidence because of the ages of things like drumlins and moraines that there has been multiple glaciations. But only where they were not erased by subsequent glacial cycles.
This is why I tend to look at the limestone under Miami. A much more complete record, which while it does not display the extent of the glaciation it shows clear proof of the interglacials.
That professor has been on YouTube a number of times and really explains things so well even the uneducated understands him. A very valuable source.