I have to deal with a lot of sidesnotes, so, I would like to "liberate" all margin for this, Here the code, as you see, sidenotes go after the page:
\documentclass[12pt]{book}
\usepackage[demo]{graphicx}
\usepackage{sidenotes}
\begin{document}
Lorem ipsum\sidenote{Here} dolor sit amet, consectetur adipiscing elit. Cras faucibus id odio quis maximus.\begin{marginfigure}
\includegraphics[width=3cm]{example-image}
\end{marginfigure} Suspendisse aliquet ante dui, sit amet feugiat magna molestie vitae. Quisque\begin{marginfigure}
\includegraphics[width=3cm]{example-image}
\end{marginfigure} pretium mollis\sidenote{Here} erat, sit amet iaculis ante volutpat ac. Proin id euismod lectus. Fusce finibus ipsum non purus volutpat, id luctus tortor congue. Duis finibus\begin{marginfigure}
\includegraphics[width=3cm]{example-image}
\end{marginfigure} arcu\begin{marginfigure}
\includegraphics[width=3cm]{example-image}
\end{marginfigure} rutrum, tempus dolor\sidenote{Here} non, tincidunt lacus. Morbi consequa\sidenote{Here}t erat\begin{marginfigure}
\includegraphics[width=3cm]{example-image}
\end{marginfigure} ac nisi viverra rhoncus. Aliquam at varius\sidenote{Here} justo.\begin{marginfigure}
\includegraphics[width=3cm]{example-image}
\end{marginfigure} Sed in commodo enim. Aliquam tincidunt velit eu pulvinar dignissim. Sed vitae\sidenote{Here} pretium nulla.
Pellentesque\sidenote{Here} sollicitudin nunc at eros suscipit porttitor. In hendrerit \sidenote{Here}tempor arcu. Cras ut tellus\sidenote{Here} tincidunt metus ullamcorper venenatis. Donec at augue diam. Ut nec magna congue,\sidenote{Here} blandit libero vitae, tincidunt sapien. Aliquam erat volutpat. Praesent eu congue\sidenote{Here} dui. Aliquam vel magna ut enim cursus viverra eget non libero. Sed lacinia lectus\sidenote{Here} ut lacus tempus, vitae mollis nisl venenatis. In eu \sidenote{Here}magna id tellus tristique porttito\sidenote{Here}r. Aliquam non semper ipsum. Vestibulum velit turpis, pharetra in urna ut, pretium loborti\sidenote{Here}s nunc. Nulla facilisi. Aliquam sed dolor dictum, tempor purus quis, consequat massa\sidenote{Here}.
\end{document}
To solve this problem, I would like to write sidenotes in all margin: Here a picture :
Obs: Any answer are welcome, even using other document class, like Koma-Script, Memoir, etc. I am using book, but I can easily move to another :)
EDIT: To make things more clear:
The sidenotes/figures/table etc begins after the Chapter, section title etc, I want to place the side notes in the whole margin, independent of what is in the body text. So, the desired result is this one:
With header:


