Itinerary template by default tries to keep blocks of relevant data together on one page while printed out or stored as PDF file.
Following is a part of the CSS code from the template:
This helps to keep the block of data (flight info for example) together on one page.
The CSS rule is applied on block of data through class like this:
<div id="sectionItin" class="spolu">
Then the whole DIV element keeps together.
If you remove class and element remains like this:
The content of the DIV will split if necessary.
Please remember to create a copy of the html template before you start with edit.