Do yourself a favor and do not fly Frontier. I flew it for the first time last August, because they had the best fare from SFO-IND (1 stop in DEN). Disaster all the way. Delayed for 1.5 hrs in SF, got to DEN, another delay for at least 2 hours and they let us sit in the Aircraft for those hours. And then they CANCELLED it! All passengers were told to unboard, and we were just left waiting at the Airport for another hour. And then they gave us a piece of paper, giving 2 options: Option 1: Cancel reservation online and get a refund. 2. Book another flight, pay for yourself, and apply for reimbursement up to $400/passenger.
No compensation whatsoever, not even a meal voucher. Not even an apology!

The next flight on United was the next day at 9.20, at $398 from DEN-IND. I had to purchase the tix for the 3 of us. And we were left stranded all night long at the airport.

So that was on August 11. It is now September 15 and I still haven't received the ~$1,200 that I spend out of pocket.

Oh they got us a $200 voucher each, but you can't even pay me to fly with them again, ever.