No subject

Standard migration takes around 30 PDs so if planned accordingly I personally don't need to have extended support.

Apart from that the following is going to happen:
The longer you extend support, the fewer people will actually start to tackle the problem.
So you will end up in a downward spiral - people won't migrate, thus asking for an even longer extend of 4.5.
The problem until then is not that big.
The real problem will be visible when CMS7 hits the deck - and there will most likely be no way to migrate from 4.5 to 7.
So it is only delaying the inevitable.