About a month ago, I had an domestic round trip between AUS and SJU via American on bereavement. I paid the trip directly on American's website with my Chase Freedom Flex through PayPal (for the 5% cash back bonus).
On the return trip, I laid over in Miami, but a passing storm in Austin caused the 9 pm flight to be canceled for weather.
The rebooking agent's next available booking to AUS would have been the same nighttime flight for the next day (a 24 hour wait), and the next best itinerary was a morning flight to IAH with a one-way rental car to be paid by me. Other nearby airports (SAT, DFW) were not available.
Ultimately, I found it simplest to book a morning nonstop from FLL-AUS via Southwest, which ran smoothly. The fare was $500, plus $100 for Uber. Fortunately, I was able to stay with a distant relative in Miami, so I didn't have to pay for a hotel.
A very kind representative from American was able to refund me to my card, but it turned out to be a paltry $85 (the determined cost of the canceled segment) out of the total $550 fare.
After reading the policy text further for Chase's trip interruption, I learned that it only covers any remaining booked itinerary items that I am unable to use (e.g. cruises, hotels, tours), not the cost of new travel to get back home. I filed a claim anyway and was denied completely, even for the cost of my original canceled flight.
After some hours of research, I was frustrated to find that most credit card travel insurance policies would not have covered this case, even if it's cheaper to buy a new ticket than it is to wait it out. A "normal" policy purchased separately might have covered alternate transportation.
Seeing as the airline may not have a reasonable alternative for a cancellation, and the cost of new travel could be much greater than the original fare, the financial risk of a weather cancellation seems unbounded, and the scenario looks likely to happen again in my future travels.
How can I protect myself from unexpected costs from a weather cancellation? Seeing as US airlines don't owe me anything other than a rebooking or a refund (of unknown amount), and alternate transportation isn't covered by many policies, is the best way just to self-insure and try for morning flights?