Hi,
right now you can change the page size to US Letter (ANSI A), US Legal, US Tabloid (ANSI B), A4, A3 and Custom size (to set any other sizing required). The notation does not automatically change size when changing the paper, but will reflow to suit the different size paper. You can change overall notation size in Score>Full Score Options>Layout - this also proportionately changes title text, dynamics, lyrics etc too, to suit.
You can also use Layout Control (Ctrl+L) to then drag systems/staves, plus use Show/Hide Resting Staves to fill out the pages with specific instruments.
-Chris