Listening to my son and daughter-in-law, they don't like snow-birds for three reasons, and the traffic is only one of those reasons.
They love to golf and say the golf courses literally double all fees/rates during the snow-bird months. My son is like me - he's somewhat "frugal" and that extra expense really galls him. And being in the mall business, he has to deal with the snow-birds, typically when someone is unhappy with something. He says they are gross, rude, and pushy.
Now, I can't relate to any of this, so I am simply stating what I hear. Talk about traffic. I have never seen worse traffic than in and south of Miami. Making the drive to Homestead was an ordeal. I don't know how or why anyone would spend their life, doing this day-after-day, year-after-year.