Put it like this Shinding - as it says on my avatar -"Rules are made for the guidance of wise men and the obedience of fools."
You may find that certain of the "Guidance" given by so called planners is incorrect and in a lot of cases they do not have the knowledge or cannot be bothered to properly research advice, and so just tell you what seems logical and easiest at the time.
To get a strictly correct answer you would probably need to consult a planning professional (do NOT go back to the council) as it is highly likely that advice you get on here is mere personal opinion. And my personal opinion would be that you do not have to enlarge your drive entrance!
However, as a parish councillor, having seen loads of planning applications and what people get away with, and having put in several planning applications myself and found out what I myself could get away with, I'll give you the benefit of my experience!
The most difficult bit of obtaining planning permission is actually obtaining it in the first place. Once you've got it people forget about the conditions that have been imposed, unless it's something you can't miss like knocking down a building before you start. So in your case, I wouldn't worry about this layout 6B. The planning authority would only come back to you if someone complained to them that you hadn't complied with this condition. And why would anyone care, even if they bothered to look up what it meant? The planners do not themselves come and check up on you. They rely on local people reporting you. I am assuming that this is a low key development that essentially does not affect anyone else so I really wouldn't do anything about your driveway.
In the worst case scenario that you really should have widened your drive, and in the unlikely event that the council get back and insist you do it, then you will have to. But it's hardly a hanging offence and they'ii just contact you and point it out. In the meantime - why go to the expense when it may never be required?