Looks like Leonida in GTA 6 is exactly what San Andreas was to GTA 5

gamesradar.com:

What is Leonida in GTA 6? The GTA 6 trailer is here, and with it appears to have come an interesting addition to the geographical world of Vice City. The word 'Leonida' appears multiple times in the video, but it seems to be a new term for the series, so what exactly is it?

The short answer is that Leonida is GTA 6's answer to the state of Florida. Vice City is based on Miami, and it's clear from the trailer that Rockstar is expanding the GTA 6 map several miles further than the city limits - a first for Vice City. So now, just as San Andreas was Rockstar's name for the state of California, Leonida is the studio's name for the Sunshine State.

In case you don't believe me, let me show my working. At the 25 second mark in the trailer, you can see a sign leading to Kelly County - my guess is that this will be a far broader stretch of open world, filled with smaller towns and many of the more rural, Everglade-style biomes that can be spotted elsewhere at the 20 second mark.

Elsewhere, however, there are a few more clues as to what Leonida actually is. At 51 seconds, a distant street sign points to the Keys, suggesting that the map might stretch as far as the semi-tropical islands off Florida's south coast - matching the imagery at 35 seconds. 

The biggest clue, however, seems to be in repeated reference to 'Leonida Man'. At 50 seconds, what appears to be GTA 6's take on TikTok features a clip from an account called 'ProjectLeonidaMan'. At 1.04, a Spanish news broadcast refers to 'un hombre de Leonida', and at 1.07, another scrolling headline reads "Leonida man sucked up in waterspout demands the city buy him a new suit."

'Leonida Man' is the best clue as to the connection between Leonida and Florida, thanks to the enduring