I don't think I would go to the USA to do just the basic JAA PPL - unless one is looking for wider options and wants the FAA PPL (and possibly the FAA CPL or IR) at the same time.
It's just too much hassle.
I did my original (FAA) IR in the USA and that made a lot of sense, compared to the 50-hour FTO + 7 exam route over here, and it cost me a fraction of what the UK IR would have cost.
The biggest thing that makes s difference to PPL costs and time is how often you can fly. If you camp out next to the school and fly twice a day, you are highly likely to do it in the min time of 45 hrs.
The UK weather is a risk, obviously, which is why going abroad to Greece or Spain is a good option.