Anyone imported their MapMyRun full workout history into Garmin?

I have over three years of workout with MapMyRun (MVP Membership) and I'm wondering if it's possible to get all of that into Garmin Connect? I've looked at so many sites that say it's possible by exporting MMR's full workout in CSV and then converting that to GPX and then import that into Garmin. It's easier said than done. I've encountered nothing but errors after errors from the many recommended conversion apps. I'm logging my runs and hikes using a Fenix3 HR now instead of the phone and hope that I don't have to lose all those years of hard work.