In my previous trips through Europe I have utilized my phone for GPS while walking through cities and towns. Coming from Canada, our roaming packages for data are grossly expensive. So I turn my data roaming off, but leave the phone on. I just use my regular SIM. This allows the phones internal GPS to function but does not rack up any data charges or phone charges. I use an APP called Maps.Me (Google Play or Apple store) and pre-download the areas I will be travelling to. Beyond address navigation, it also has most landmarks, stores, restaurants, etc already loaded. You can mark your own places, like your hotel, go wander and then easily find your way back.
It's a cheap alternative to a GPS device, or buying a SIM card for your phone for navigation. I've never used it in a car and had voice prompts off, but it kept up quite well on a train in Ireland with no real lag as to location.
Just my 2 cents worth.