Though this is already going off topic rapidly, I have to chip in and give this thread the final blow into "off topic doom": I recommend uMatrix, uBlock Origin as well as "HTTPS Everywhere" as browser add-ons. They help quite a bit with keeping web sites in check that use stuff like Google Maps, especially uMatrix. With uMatrix you could browse the Film Photographers Map without Google knowing it (you won't be able to display maps or enter your location, though). All of these browser add-ons should be available for Chrome variants and for Firefox.
To get slightly back on topic: you could suggest to the site's maintainer to switch from Google Maps to OpenStreetmap. However, he'll need to replace the Google Maps' location finder with a service that will allow for putting coordinates to a postal code (something that OpenStreetmap doesn't do sufficiently well) and these services hardly ever come for free if you want to use their APIs. That means that either sites like the Film Photographers Map start costing money so that they can afford the fee for the API access to a GIS database or we need to live with the fact that Google knows that our IP is currently looking at a certain map on a certain site. Don't get me wrong, Kai, I'm with you regarding data privacy and I respect your motivation not to participate.