I don't fly till March but I really don't see a problem. I traveled on the near-free fares with NW to Europe twice in the past six weeks. No problem. Even almost got bumped off one flight in exchange for a $300 voucher.
The check in people and GA's don't care how much you paid for your ticket. If something was going to happen, it would have happened long before you check in.
Enjoy your time in ACA.