I have the same problem like many others. In the “DWD Unwetter Binding” is the text of the description often to long for the Sitemap. So I searched for a solution.
I found some ideas, like put everythin in frames or something else. That was all not what I have seached for.
Now maybe I have a better solution.
I take via REST from the “Beschreibung” item the JSON value from “state” which is the description. The Transform this in a html file and display it with the webview in my sitemap.
The style is not perfect at the moment. And because I have never worked with html or css previously the code is probably not well.
This my code:
The local skript I´ve used is jquery. You can download it there:
Then you have to save it in your openhab html folder.
Or refer to an online version of it: https://code.jquery.com/jquery-3.2.1.min.js
I prefere the local version
ps sorry for my bad english, my school days are a long time ago