I now pair my Garmin for quick uploads of completed rides and for text or phone number notifications while riding.

But I still load routes into it by plugging it in via USB on my PC. That works fine. No phone is needed for uploading routes, copying completed ride recordings to my PC (and then I could upload those recording files to rwgps or strava), or installing updates. When plugged in, the Garmin appears as a USB drive -- just copy files to or from the correct folders.