It probably won't give directions, which I guess is calculated at the web site, but even without data, you can use the cell phone to see where you are on the map. Just dl the maps when you're at a wifi source. I forget the details but google maps last iirc 3 months and maps.me might last much longer. Maps.me has the advantage that it displays house numbers. Google will find a house by number if you put the number in, but maps.me (on the PC too) displays the whole street with numbers for every house or maybe at the ends of each block. There are other advantages to each one too. But they both work for telling you where you are and you can enter a destination and find out where it is, on the map, assuming you are in an area for which you have dl'd the map. (If you had data, it would dl the map on the fly, as you drive into new areas, but I usually have all of central maryland and wherever else I plan to go soon. For the trip to Florida, I dl'd the whole path to Florida.
Even without a monthly plan. Just about any phone, even that someone has stopped using will do this.