Thanks Jon, your advice pointed me in the right direction. It was the same origin policy blocking me.
My solution goes a bit off topic but hopefully will help others.
In the end I rolled my dashboard into a node-webkit app and disabled Chromium’s same origin policy with the following line in my app manifest file:
"chromium-args": "--allow-file-access-from-files --allow-file-access --user-data-dir"
The line in the html output should be:
"topojsonURL": process.cwd() + "\\files\\topojson\\"
To prevent “process.cwd()” being added as a string value I did the following in Python:
html_plt = plot(fig, output_type='div', config={'topojsonURL': '*process.cwd()*' + '\\' + 'files\\topojson\\'})
html_plt = html_plt.replace('"*process.cwd()*', 'process.cwd() + "')
I then just wrote “html_plt” out as a html file.
Loads fine without a connection or server 