I just navigated all over northern california and southern oregon for 2 weeks... before I left, I told google maps on my phone to 'save' the maps of all the areas I'd be traveling through, so even when I was out of service range, it could find places and routes... it worked great for me.
I just use my Garmin as it covers rural areas, dirt, roads, etc. I do have
Topos loaded, but rarely use them as the are great for hiking but I don't need the detail for driving.