We had a chance to run some more simulations, so I thought a little more about the test program that tries to maximize power consumption.
I had eight cogs executing from register memory at 180MHz. I made their loops in hub memory, instead, which forces frequent FIFO reloads. The simulation showed a worst-case power consumption of:
That measurement was taken at fastest process corner, highest voltage (1.98V) and lowest temperature (-40C). I don't think a customer will ever see more than 2 Watts consumed by the core. So, the original estimation of about 2 Watts is probably accurate.