Why can't it be more like
Dunsfold Park, in Surrey, England? It's a business park, with a racetrack, and an airstrip. For those who watch Top Gear on BBC, you'll know what I'm talking about.
Then again, the decision has already been made. For whatever reason why the airport needs to be closed, I'm sure it's for the better of Edmonton.
I'm sure the Edmonton Indy would be there for the remainder of its contract, once the airport closes. After that, it's up to the IRL if they want to remain there, or whatever plan that the city has in mind for the airport forces the IRL to go somewhere else.