Thanks!
There's a quick way and a slower more compact way. You basically undo the frame bolt and swing the front round which takes probably about a minute. That's the quick way.

On the original twenty there is also a quick release on the handlebars so you can rotate them 90° once you've inverted the frame but with a non-stock quill stem you need an allen key so it takes longer. Plus you can put the seat down; So I guess with practise and maybe if you kept the right sized allen on your keychain you could get it as small as it goes (it's no brompton!) in about 2-3 minutes or maybe less.