yes, you can.
Being based in Hong Kong I did my training in Florida (EFT), where I also went for all the theoretical exams, at the same time as the practical training. Some of the students came there with all those exams already 'in the pocket' as they first passed them in the UK (among others an 'expat' in Spain who did all his paper exams in the UK, a bit like you). I understood you do not have to be a member of a club or registered in a school for this. There might be more info on CAA's website.
There are also a few threads , among others one from Backpacker and one from Destinationsky, where you can find more information. If you do have spare time do them first in the UK. If not then combine it all in one go, but be prepared that in such case these are no 'holidays' if you have only a few weeks time.
Hope this helps. Herewith the threads:
Destinationsky's:
PPL Training in Florida - an honest View
Backpacker's:
Guide to obtaining a JAA PPL in the US (part 1)