I too was in the same position a few months back regarding doing the CPL at OBA or in the UK and could only get 3 weeks off work.
I did it here in UK in the end , the main reason being that if the training over-ran for some reason ( aircraft u/s, unavailabilty of examiner, i get flu or 100's of other possiblities!) then it would mean coming home without finishing and the extra cost( and extra leave from work) to return to the states.
As for the weather , I did my hour building out there and it can throw up a few surprises so you still have that aspect to think about, and some airspace is very busy,OMD/Daytona, just make sure you dont get rusty on your UK flying.
Lastly DO NOT go in with the glorified PPL theory as you will be in for a surprise(talking from experience!). The PPL skills are used for sure but its about building on them and developing your skills, confidence and decision making.
Good luck whatever you choose and, most importantly, enjoy it