[01/09/2020 @ 4:31 PM] Still available. Less availability than last month.
Southwest has round-trip flights from Austin (AUS) to Denver or Chicago (DEN, MDW) for $98, NONSTOP. $49 each-way. Most flights are between January and April. Mostly on weekdays. Origin/Destination reversible.
Note: You can save up to an additional $150 if you book your Flight+Hotel together as a package on Southwest Vacations and use the US150OFF coupon-code at checkout. Before you commit, always compare the prices of the individual Flights and Hotel with other hotel booking sites like Expedia or Tripadvisor.