Your Chisos boots will last decades with appropriate attention. The vamp (leather surrounding the foot) and leather shaft require only minimal care. Condition this leather about once every three months. Store in a cool, dry location and take a day off between heavy uses to allow the insides to properly dry.
The leather soles of your boots are designed to wear out and be replaced, much like the brakes on your pickup truck. Your mileage will vary depending on conditions of use, your weight, and your walking style. Avoid repeated exposure to water and excess moisture. When needed, a cobbler can perform a full resole and heel replacement.
To extend the life of new soles, have a cobbler apply a rubber sole saver upon receipt. No matter what, physics is going to win against leather soles and stitching. To slow the process, a cobbler can add some rubber to mitigate.