I just KNEW it was a good idea to hang on to all those old roadmaps from days gone by...
Oh sure they'll be outdated in some aspects, but largely, roads and highways don't just get up and move themselves....
And they laughed when I said I don't wanna throw them all out....
Breaking GPS won't break digital maps. They'll still work just fine, and will be up to date. The devices just won't be able to identify your current location, you'll have to work that out from context, the way you do on a paper map.
Or not... our smart devices use other signals in addition to GPS, to help address the fact that GPS requires a relatively clear view of the sky, and that's not always available.
Circa 2010 I navigated halfway across the country using Google Maps running on an iPod Touch. The device didn't have a GPS receiver, but I didn't even realize that for quite a while because its database of known Wifi locations was able to give me reasonable location data most of the time. Once I understood that constraint I was able to use it quite effectively. I expect that the databases of fixed Wifi and BLE beacon locations have gotten much more extensive and effective over the last 15 years.
I inadvertently repeated the experiment about four years ago. I bought an iPad to use for navigation while sailing, not realizing that Apple only includes a GPS receiver in tablets that have a cellular modem. I spent a little time experimenting with the Navionics app on land, making sure it would work for me, and it worked just fine around town and even in the moderately-rural area where I live (I have to admit this testing was cursory). Then when I got a few miles offshore, the stupid thing stopped updating its location. I decided it must be faulty and switched to using the app on my Pixel phone to double-check my location, still using the iPad's larger screen for charts (including using the charts with azimuths to visible reference points to calculate my location -- a good habit when navigating in coastal waters, to maintain the skills).
When I got home I mentioned the situation to a friend who is a private pilot and uses an iPad for navigation while flying. He asked me whether my iPad had cellular data and explained that Apple uses a single-chip solution for GPSr and modem, so an Apple device has both or neither, and told me to exchange it for the more expensive iPad. I exchanged it for a Samsung tablet because it pissed me off that Apple would even make a smart device without a GPS receiver.
Anyway, my point is that if the GPS network went out, your digital navigation might not even notice for a while. And even if you lost location service entirely, you'd still have maps. Maybe if there's a massive EMP that knocks out all electronics you'll get use of your paper maps. Though you'll probably have to do it on foot or on a bicycle.