I'd use a smartphone to snap a few images while out shooting film to correlate to those images.
Depending on how comfortable you are with the idea, you can turn on the 'personal timeline' in Google Maps on your smartphone and it will keep track of your travels each day. Sometimes it works very well and sometimes it's not very detailed, but I have used it to re-remember where and when I've been. Yes, there's the 'big brother' aspect of it all...
If you're not a big fan of smartphones due to the big brother aspect, you can still use one but not connected to the network. The camera will work and GPS should also work independently as it's a passive system; the phone receives signals from the GPS satellites, which should still embed in the photo EXIF (though I have not tested this, but I have used GPS to follow on offline maps when no network connection was available, i.e. on a flight or while hiking remote areas). The reason a smartphone comes to mind is it's compact and easy to carry along day-to-day while out shooting with other gear. It also makes for a good clock, flashlight, etc.