So far the easiest way I've found to copy my text and graphics from a calendar is ugly but is the only workaround I've found remotely tolerable.
Create a new blank calendar using your "Understated" template. Open the previous year (that you
should have been able to just change the start/end dates on). One month at a time, in the right-hand pane click Ctrl + a to select all your text & graphics, then still holding the Ctrl key, deselect the month
text box and the calendar grid - the thick border around the month (or you can delete them on the new calendar after you paste, the new year is underneath), go to corresponding month on the blank calendar, Ctrl + v to paste.
Like I said, ugly...but if you have a lot of graphics and customizing that will not carry over like I did, this can be a lot easier than having to start over.