Have uk driving licence moving to france...when my house sold I wont have a uk address ..is my licence valid to drive on last known address? ..in the interim whilst I get new address ?
In principle, you just notify DVLC of your new address. The fact that it is France is not a problem. As the law stands at the moment, you can continue driving on your UK licence until it needs renewing (at which point you will have to replace it with a French one).
However unless you have been living under a rock for the last two years, you cannot have failed to notice that the UK is currently committed to leaving the EU on 29th March (although informed opinion appears to be that this might be pushed back by a few months). Unless the UK leaves with a deal which involves a transition period (which is not looking particularly likely at the moment), your UK driving licence will cease to be valid when we leave.
UK government advice is that you should exchange your UK licence for a French one before 29th March.