Not much of a turkey breast fan but will try a Perdue oven stuffer roaster next time. I do understand your reasoning as frozen poultry seems to take a year and a day to defrost. I have had years of success of just putting all the frozen meat inside a tightly sealded cardboard box inside my checked luggage. Travel time for me is freezer USA to freezer DR never more than 8 hours.
i prefer doing the checked luggage method. Never had a problem clearing customs at SDQ, got some strange looks but they never confiscated a thing.
I am guessing a chicken may work as well.....although the legs and wings would likely unthaw fairly quickly....thus why I use the frozen turkey breast 3-5 pounds. Those things take forever to unthaw.....and thus the reason they make an excellent ice substitute. Besides, when I am ready, I can also have a nice turkey dinner.....
My freezer to freezer time is about the same as yours....usually around 8 hours.
Carryon or checked is usually a space available decision for me. Normally, I am also bringing whole wheat bread, bulkies, or hamburg rolls (Dominican bread is awful in my opinion)....and those items definitely survive the trip better in carryons.
While I too have never had a problem with Customs, but as you likely are aware, you are supposed to declare any plants, vegetables, fruits, meat, fish or poultry.
Bon Apetit.
Respectfully,
Playacaribe2