[Tex/LaTex] How to autorotate pdflscape landscape pages when n-upping

Question

I'm using pdflscape for my landscape pages in an A5 portrait document. Then I use the following command line to prepare the PDF to be printed on A4 paper:

pdftk blank.pdf document.pdf output padded_document.pdf verbose && pdfnup --paper a4paper padded_document.pdf

The resulting padded_document-nup.pdf, however, has all the landscape pages still in landscape in what amounts to an A6 format, instead of having them rotated and in A5.

Is there a way to automatically rotate them so they will appear in the intended size? I know I could replace pdflscape by lscape but I keep forgetting that and it'd be nice to have a solution that doesn't involve changing my document each time I want to print it. So either a clever trick in the PDF or something I can put in my command line.

\documentclass[a5paper]{article}
\usepackage{mwe}
\usepackage{pdflscape}
\begin{document}
\blindtext\blindtext
\begin{landscape}
\thispagestyle{empty}
\begin{figure}
\includegraphics[width=\linewidth]{example-image-a}
\caption{Landscape figure}
\end{figure}
\end{landscape}
\blindtext\blindtext

\blindtext\blindtext
\end{document}

Which as 4-up with page borders (not the desired 2-up without borders but you get the idea) looks like this:

What it should look like is this:

I faked this last one by just using lscape instead of pdflscape.

Answer 1

pdfnup uses pdfjam, which in turn uses the LaTeX package pdfpages. The latter one knows the option rotateoversize, from the documentation:

This option allows to rotate oversized pages. E.g. pages in landscape orientation are oversized relatively to their portrait counter- part, because they do not match within the contour of a portrait page without rotating them. By default oversized pages are scale and are not rotated. Either true or false (or no value, which is equivalent to true). (Default: rotateoversize=false)

This option can be specified on the command line for pdfnup or pdfjam:

$ pdfnup --paper a4paper --rotateoversize true test.pdf