Food carts are a great idea but like many things seem to carry the typical Vancouver premium price.
The last few times I've been in portland I liked the permanent parking lots they have with food trucks. Only 50% of them seem to be open at any given time, but the food is good (selection is awesome), prices are good too. The problem is no tables or seating. I don't recall any generators either, I wonder if they get power hookups from the city.
It will be interesting to see if the COV rigs something up for this event (power wise). It would be the green thing to do...