
I just had a peek at what litters are advertised on the Puppy section here and there are 3, none of which would be within 20 miles (IOW?) of where you are. One says N.Devon, another Looe, Cornwall and a third in Cullumpton, Devon. Sometimes people with litters from working lines advertise in a local newspaper.
You might be more successful if you go via the relevant Breed Club most of which have somebody keeping a record of members with puppies available, at least that used to happen. The KC has lists of litters although using them is no guarantee of the quality of the litter - just that the breeder has paid the listing fee! Only once did I have my name added to their list but found myself alongside a well known puppy farmer! I never did that again.