You can get a PPL anywhere. It doesn't have to be UK/EASA either. I'm guessing Guernsey is going to be expensive? You can get an FAA Private in about 4 weeks if you show up prepared, and having an FAA certificate will help keep your hour building costs down. You might also consider Spain or anywhere else that is warm. The weather is going to be your biggest enemy - what takes 12 months in the UK will take 2 months somewhere sunny, and time is money. You'll spend about 30% of your budget getting the PPL and ATPL exams, but that will represent about 75% of your time and effort.
Consider the time period between now and age 65 as a conveyor belt with the end representing retirement. What could you be earning in that final month? £15k? That's what you're losing every month that you delay following your dream, so get cracking!