Thats probably an issue, not with FamilySearch - but with your Printer setup and how you are printing it. (which can be different from one computer to the next and depending on configuration)
What I normally do is PRINT to PDF - using the "options" link on the right hand side for PRINT - and also assuming you have a pdf print option on your computer - which will generate a pdf file on your computer.
And then, if you really are - intent on a physical copy - open the pdf and then play with your different printer settings from within Adobe (portrait/landscape, fit to size, different paper sizes etc. ) before you actually print it to ensure it will print as expected.
also if you are interested in a LARGE chart format of the fanchart - you might be able to take the pdf (on a flashdrive) it to an office supply store and have them enlarge and print on a large size printer.
you can use tools like ILOVEPDF to convert the PDF to an image file (JPG) and then resize or re-orient the image to print the way you want.
the tricks above can work with many different items in FamilySearch (or elsewhere)