"They went to Florida for the winter." means "They went from the beginning to the end of the winter."
So, "for" here shows a reason why we went to Florida, right?
I am sure we can say "I lived in Florida for 2 years".
But I am not sure if people say "I went to Florida for 2 years"??? Does it mean I arrived in Florida & hung around there for 2 years???
But "I had been in Florida for 2 years" sounds ok.
So, What does "They went to Florida for the winter." mean?