Clone the Windows partition with Carbon Copy Cloner?
Look into finding a copy of Winclone.  The main problem for SuperDuper and CCC is the inability to write to NTFS volumes.  They can backup your files, but often not necessarily capture the extended attributes with regards to ownership and permissions etc, resulting in an inability to make a sensible restore.

Winclone is no longer in active development, but it is effectively CCC for windows/bootcamp partitions.  I've used it to transfer bootcamp partitions from one drive to another in the past.