I agree that LAX
would be problematic, if only because of the lack of gates.
Howsumever, one problem for Frontier is this: they are building a fairly loyal customer base (LCB), and with the great tv ads going national, they base will probably improve.
The drawback for (some of) Frontier's LCB is that presently limited to flying through DEN
. There is no north/south flying.
So while the competition is fierce on both coasts, I could imagine Frontier doing a couple of 2 x daily on some of the better coastal routes. Not as "competitive" business, not as a fight, but giving the LCB a choice.
Or not even purely coastal. An alternative way for Frontier's customers to get from - say - SFO
to Chicago might work.
Then again, with today's announcement of the deal with Horizon, which will effectively double the Jet Express fleet, plus the rumors of red-eyes from DEN
to Florida this winter, Frontier appears to be in a good position to do pretty much what it wants.