You don't have to, it's just for fun. Your airport can be anywhere, some people choose one close to them or that they're otherwise familiar with, some choose a famous one. A list of airports can be found on the first post of this thread (down a ways at the bottom, though). There's no hurry!
Oh OK, I'll play.
I choose the Penn Yan Airport; which a) is somewhere more or less near to me and b) would fit with a so-far-not-written-up headcanon in which there are survivors on the Keuka Lake Bluff*, who survived by walling off that piece of land (which sticks out into Keuka Lake, and has farmland and a college/nursing school for info and for dorms for refugees) and with considerable aid from Haudenosaunee ancestors and spirits, and from some mountain lions who turned out to be alive in the area after all.
The Penn Yan Airport isn't on the Bluff; but it's close enough for wintertime excursions. So having a helpful Master there might well be useful.
And congratulations current and belated to everybody on this thread which I haven't been reading before!
*note that this might not work in practice, as I'm not sure whether the lake branches are wide enough to prevent trolls from crossing; and they'd have to build miles of wall in a tearing hurry, and realize fast enough how to set up quarantine. And I doubt I'd make it there, myself.