I wonder if one could simply use LaTeX \\newpage command in R markdown v2 in a different way than this:
\\newpage
```{r, results=\'asis\', echo=FALSE} cat
You can make the pagebreak conditional on knitting to PDF. This worked for me.
```{r, results='asis', eval=(opts_knit$get('rmarkdown.pandoc.to') == 'latex')} cat('\\pagebreak') ```