The high season rates for nearly every hotel in Cape Town will start from 01 October (and for many from 01 September) and run through until 31 March or 30 April. So from a tourist point of view, October and November will be little different in my opinion.

From a weather perspective the later you leave it, the further into Summer you get, so theoretically, the "better" the weather. However, that is very much theory. You can have wonderful weather in October and in November, and you can have terrible weather in both months. The reason I say March is a great month is the weather is still warm, but usually the wind has died down. Wind for me is the worst weather factor you are likely to experience in October/November.

Not sure if that helps at all