Isn't about time motoring organisations/press put pressure on the government regarding renewing over-70's licences? They are allowing cars six months grace for MoTs. A lot of over 70's need their cars to go shopping. Please don't quote home deliveries as an excuse as it is very difficult to get a slot, usually not at all. However, I found this on the DVLA website:

You can drive while your licence is being renewed if you meet all the following conditions:

you have the support of your doctor to continue driving
you had a valid licence
you only drive under the conditions of the previous licence
your application is less than a year old
your last licence wasn’t revoked or refused for medical reasons
you’re not currently disqualified
you weren’t disqualified as a high risk offender on or after 1 June 2013

This would appear to say it's OK, so long as you've applied, depending on how you interpret the second and third one.