... We think it will be under tropic airs size requirements.
...
I wouldn't worry too much about this. I used to come back with full sized coolers weighing A LOT. Planes can get full so you cannot be so picky about flying on the same plane with anything over size/weight, but Tropic will get it there. Worst case, you can always send it cargo on Tropic, paying a maximum of $5us and it WILL get to you. Have the number for your hotel ready to give to the passenger/cargo attendent at BZE.