Long before mobile smart phones, truckers were using apps like copilot gps on their offline laptop for just this. I used to have it on a laptop for install work I did. In fact, I continued using it in areas with no cell coverage. Another app I used was Microsoft Streets and Trips. In 2006, they added a GPS version that did turn by turn nav.

That said, the point still stands. I did some searching, and Streets and Trips are discontinued. Copilot was bought by Trimble and AFAIK, you can only get the mobile app versions (they still have offline support). I think their truck fleet software will still run on laptops, but are sold as part of a bulk purchase.

I did find MapFactor, which I've never used, as being something that will work on Windows and Linux (via wine) and it provides real-time GPS navigation.

https://www.mapfactor.com/en/products/navigation-software-st...