I've created and published many videos to sho.co previously, however my most recent video just won't publish.

It's been going for over 19 hours and still state publishing.

I can render it and save it down as a file, but it's about 75mb so ideally I want it hosted so I can link to it.

Any ideas?

You may want to save your project online to the cloud folder and raise a ticket asking customer support to look at it.