The limestone (marine shell accretions) in FL are about 100 feet higher than the present sea level. That gives an idea of how high sea level will eventually be before the next ice age. If it happened in prior inter-glacial periods it will likely happen in this one.
That is a wrong conclusion to reach. Another conclusion is that at some time those limestone deposits were much lower and plate tectonics has forced the plate upwards. There isn’t enough water on Earth to raise the sea levels another 100 feet.
The three previous inter-glacials were much warmer than this current inter-glacial which is about to end according to the ice core records. Solar insolation started to drop about 8,000 years ago. We are now past due to catch up to this drop.
https://www.ncdc.noaa.gov/abrupt-climate-change/Glacial-Interglacial%20Cycles
The Virginia state fossil is Chesapekten Jeffersonius, a really big scallop shell. It is found in the exposed river beds along the coastal plains in VA and NC. They didn’t swim upriver and climb up the banks to imbed themselves in the mud. The seas were much higher.