As I've said before, when it comes to legal stuff, the details actually matter.

Generally speaking, the "six months" analysis tends to come into play for DIS-claiming residency -- usually in a high-tax state like NY, which (if memory serves) I believe has a statute on the subject.

Actually CLAIMING residency in a state, in this case Florida, is really mostly a question of your "intent" (along with a physical place to hang your hat). Florida law, for example, provides partly as follows when it comes to claiming residency for property tax exemption purposes:

"Intention to establish a permanent residence in this state is a factual determination. Although any one factor is not conclusive of the establishment or non-establishment of permanent residence, the following are relevant factors: (1) A formal declaration of domicile by the applicant recorded in the public records of the county in which the exemption is being sought. (2) []. (3) The place of employment of the applicant. (4) The previous permanent residency by the applicant in a state other than Florida or in another country and the date non-Florida residency was terminated. (5) Proof of voter registration in this state. (6) A valid Florida driver’s license."

It goes on from there, but you get the drift.

Accountants and lawyers who specialize in serving the ex-pat community are way more versed in this stuff than I.