I used usb-otg for moving routes to my edge 810 and activities to strava (had to use the 'desktop' version of the website - not sure about the app) a few years ago on a tour. Had to be careful not to leave it plugged in though, it would charge from my phone and drain it pretty quickly.
Thanks both, good to know this is possible.
Can you also get the ride data off and upload to Strava?