By default, DyKnow Vision panels are small rectangles. You can print landscape-oriented panels from Adobe Reader to DyKnow Notebook Writer
The best solution is to have the students use the Zoom feature in DyKnow. During class, ask the students to click on the View tab at the top, then Zoom. they can change the zoom setting from To Fit, the default, to 100% or greater. This will allow them to easily read and interact with the PDF document.
They can also press F11 on the keyboard for full screen, though this may not make the document as large as they need.