Hi,
You can set HtmlToPdf.Options.ZoomLevel to a small value such as 0.5. The reason that it gets chopped off is by default, a PDF "paper" is narrow than a browser window. The default PDF paper size is 8.5 inch wide, excluding margins its only 468 pixels. If you resize your browser window to that size, you will see it chops off the HTML as well. Setting ZoomLevel to a smaller value increases the pixel width of the "window" used by the converter. If you set it to 0.5, then the pixel size doubles as 936.
The converter is also able to automatically detects the minimum width of your page and adjust to it. So if you have something like this: <div style="width:1000px"> </div>, then the converter will see it and automatically adjust zoom level so that a converter "window" is at least 1000 pixel wide.
Thanks!