I played a lot with the differed available penalties. But I cannot achieve what I want. Here an example for explaining:
\documentclass[]{article}
\usepackage{lipsum}
\usepackage{multicol}
\begin{document}
\lipsum[1-4]
\begin{multicols}{2}
%\raggedcolumns
\lipsum[4]
\textbf{\lipsum[5]}
\end{multicols}
\end{document}
I want to prevent that the last paragraph stretches over two pages. So the bold printed part should go on the next page. The rest of the 2-column text should stay on page 1. It may use \raggedcolumns, that would be okay with me. A \newpage after \lipsum[4] would do the trick, but how can I make LaTeX insert it for me?
EDIT: I need to clarify: The content of the 2-column text is coming from an external source. I do not want to edit it manually: No page break, no environment, nor any other change I need to do to change the 2-column text. Just \lipsum[4-5].

