I think we're mssing the point here a little.
Funfly said in his original post that he had a diversion, but it had become unsuitable. The question is hypothetical, and it acknowledges that however good your planning, things sometimes don't go according to plan. The question is quite legitimately asking what to do in these circumstances - it already assumes, I think, that all appropriate precautions had been taken during the planning phase, but that this is not sufficient on this hypothetical day.
Gus has an excellent point, btw - UK 1/4million charts show runway directions. Incidentally, US charts all show runway directions too. I've never used a UK 1/4million chart, but I remember finding runway directions very handy on US charts.
FFF
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