Down South

Native-speaker intuition from Scots and Scottish English speakers wanted.

What exactly is the meaning of "Down South"?
I have the impression that the general meaning is 'England', but I also have the impression that the picture is a little bit more complex than that.

• Is the default meaning 'London and surroundings', if no further information is specified?


• Does Northern England qualify as Down South? (Places like Manchester, Liverpool, etc.)


• Does the English Far North qualify as Down South? (Places like Newcastle, Berwick, Carlisle, etc.)
  
  
  • If people say they are going Down South, and it turns out they went to Manchester, Newcastle or Carlisle, would you think they had lied to you?
  
  


• Is Wales part of Down South?
  
  
  
  • If you were going to Wales by land (i.e. through England), are you going Down South?
  
  
  • If you were going to Wales by air (i.e. not through England), are you going Down South?
  
  
  • Is a conversation "How was your trip down south?" "I didn't go down south, I went to Wales" grammatical?
  
  


• Do even the Borders qualify as Down South? (I don't think they do, but if Berwick does, then where does it end?)