If you retain your UK address, yes you may keep the licence. If you move from one address to another in the UK strictly speaking you must inform the DVLA in Swansea. We lived in Swansea for five years so I renewed there, the UK licence I turned in for a French one in fact. I turned up there to replace my expiring one and had a wonderful lecture about the fact that when I had moved from the address on my licence I should have informed them, then got a second glare when I cockily mentioned the fact that when we sold up but before ready to move to Wales we rented for a couple of months near my old address. We should, according to them, have informed them I had left my old address, given the temporary one and then done so again but then being in Swansea for over a year on my address before the last was simply against the law. So yes, if you remain at the same UK address for longer than your UK licence is valid of course you can retain it. The fact that 'nobody' bothers is not a valid argument if you get into trouble. By moving out of the UK whilst your licence is indisputably valid, your address is not, therefore you are legally obliged to change it. If you retain your UK address legitimately then fine, if you have no UK address then not. If as my wife, you get a single point taken off then you have no choice, kick and shout in protest as you may.
The fact of the matter is that none of this is made clear, the details about change of address need to be better informed and the realities of driving on a UK licence that is revocable also made clear.