Be careful with this.
While it may sound like a good idea, it literally violates the U.S. Air Carrier Access Act and SAS (the airline) was recently fined for doing exactly what you describe[1].
This solution may also create a situation where the accessible website becomes a "second class citizen" in terms of content because managers are not willing to allocate resources to improving the dedicated accessibility-friendly version. I argue it's much better to make a11y a part of the specification process just like we did with the responsive web when we abandoned WAP.