How do I archive my iMovie project to a network drive?

I spent weeks on my first iMovie project and I think I have it just right... for me.

The problem is that there is the potential that I would want to customise the exact same event for other people involved. For example, two people have expressed interest in a copy personalised to them but have not yet sent me any personal content.

Even If I never create another version of the movie I'm still reluctant to delete all those weeks of work.

Result; I have 30GB of iMovie data parked on my MacBook and I am finding that OS X loves to unnecessarily duplicate data so HDD space is a premium.

Meanwhile I have TBs of space on my NAS.

I have googled my brains out and the closest I thing I can find to archiving an iMovie project is this...

https://support.apple.com/kb/PH2289?locale=en_US

...but that's not even for the current iMovie.

I thought maybe mounting a network share as a HDD might be an answer but it isn't clear whether that would help and it also isn't clear whether I can mount a drive in that manner (as I would under Linux or Windows).

As you can probably tell, I am new to Mac. Can anyone tell me if I can archive the whole project rather than just exporting a video?

Thanks,

Glen

MacBook Pro (Early 2011)

El Capitan

iMovie 10.0.9