Another alternative to geoIP could be WiFi-based location detection (comparing which WiFis are near you to a database). https://beacondb.net aims to replace Mozilla's shut-down location services, with public data releases once a proper anonymisation scheme has been figured out to avoid another Mozilla event. Google and Apple apparently also have usable back-ends: afaik it's not documented or meant for public use so ymmv, but the reverse engineered API is apparently super stable and not requiring any auth.

In case you have a second device where you'd like location, or ever don't have the USB GNSS receiver on you or something :)

Yep. When I was screwing around getting geoclue to play around with NMEA sentences, I ran across beacondb. I might replace geoclue's back end with it next time I feel like messing around.