This might help. It should give you a good idea of how busy the airport will be. I'd check departures 1 hour before and 1 hour after your flight is scheduled to depart. The more planes in that two hour window means the busier the airport. Airline have always said be at the airport 3 hours before departure. Having said that, we have on occasion been on time only to find no one at the checking in counter. If it was me, I'd get there early, check-in and then go sit at The Groovy Grouper or go upstairs and have some lunch at Margaritaville. I like The Groovy Grouper thing because you can check the security line every once in a while to see how busy that is. Also you can make a game at the airport exit door. See how fast it takes people to shed the fleece jacket or get the knee high leather boots off.

https://www.mbjairport.com/flight-information