Ok -- digiKam is EXCELLENT photo management software. I've got about 10 hours in on tagging, which is just tedious but straightforward and necessary work.
I'm doing all my "road trip" photos first, about 1600. I feel like I know them better now and some tests of locating things is a big success.
A lot of care has gone into data integrity. Built in code for migrating and exporting databases. This is lovely stuff. I'm now a huge fan and kinda awed that this is free software.