To make a copy of your roadmap, the workaround is to export your roadmap to a file. Exporting to a file is essentially taking a snapshot of your roadmap.
Once exported to file, you can either re-import the roadmap and then you will have two instances of the roadmap on your home page. Or, keep a copy of your exported file in a backup area. Note, the exported file is timestamped so you know when the export was taken.
Also, if you do re-import your roadmap file, you can now change the sub-title to indicate the version number, like below.