If using increased V2 performance, the V speeds will be artificially high so its a bonus if you have an idea of what speed the ac will actually fly at. On the 320, for the same weight, temp etc, it was possible (in my day) to have V speeds that differed by 30kts on different runways (120 - 150kts).
So:
Consider TOGA
More flap to reduce stall speed?
Rotate when above 'flying speed'
Its not your day, but you might just get away with it.
mcdhu