How to convert HTML into endless one-page PDF via wkhtmltopdf?

The wkhtmltopdf 0.9.6 Manual documents this parameter :

    --page-height      <unitreal>      Page height (default unit millimeter)

Therefore defining an enormously long page can be done via :

--page-height 10000cm
--page-height 100m

which both define a page of height of 100 meters (I mention both in case your wkhtmltopdf does not support m).

Not using wkhtmltopdf, I do not know if there is some upper limit to page-height, but you can find that empirically.

In addition you can try to add --disable-smart-width (width is not an error) and try for the moment the less ambitious --page-height 100cm.

In this man page there is a comment about disable-smart-width that it's only available using patched QT.

There is also another comment:

On the wkhtmltopdf website you can download a static version of wkhtmltopdf at http://code.google.com/p/wkhtmltopdf/downloads/list. This static binary will work on most systems and comes with a build in patched QT.

The project has moved elsewhere, so you might hunt there for such a version, or ask in the forums.