Dynamically fill webform

I would like the ability to dynamically populate fields on a web form based on other fields within the web form.

As an example, I have a form that can be filled out by a representative from any school district within the county. The form has a field for the district name and fields for the district’s contact information (address, city, state, zip, phone, etc.). I would like the ability to prefill the contact information fields with conditional logic (i.e. if District name is <name> then address is <address>).

According to my question HERE, this functionality can only be achieved by making a set of address fields for each district and then making only the currently selected set visible. This becomes exponentially cumbersome as the number of options in the trigger increase and the number of dependent values increases.