If you don’t want offline maps, and you don’t want to use data, what exactly are you looking for? The map has to come from somewhere.

How so? That makes no sense. Obviously you will have to make sure to have downloaded the maps of the area you’re going to be in before going into that area, while you still have access to the internet. You can do this any time before leaving!

I think you might have an old budger phone.

Budget phones are notorious for having very inaccurate GPS antennas, so the locations would be wild all over the place (I know from experience). If you used such a phone, you’d assume that you need internet for GPS, which isn’t true. (I had thay assumption once) GPS is a separate part of your phone, and should be reliable even without internet.

Midrange phones should have a reliable enough GPS, and perhaps even budget ones, if it’s modern enough and from a reputable manufacurer.

Since you mentioned the US, you can go to Bestbuy and just look though their GPS units, they are anywhere from $50 to $200, those standalone units should be the most reliable, but for those, you’ll need to update the maps via a computer frequently, or you might end up getting directions through a road that might not exist anymore.

Or just any modern phone with a local pre-downloaded map would work as well, although phone GPS is slightly less accurate than a standalone GPS unit. Phone maps would be easier to update, becaude you don’t need to download extra software or connect to a computer.

IT guy here, what is the end goal you want to acchieve

In that case I would recommend a map book that covers the local areas.

If you’re going to be in national forest land, the Forest Service has maps you can use in Avenza Maps that are geotagged - probably the wrong term but they work in areas of the forest with no cell service and it still shows where we are and even when we’re moving.

Other federal agencies (BLM, FWS, etc) may have them too. You could even see if the area’s counties have some? I only have direct experience with USFS maps that do this but I doubt they’re the only ones.

Eta: After looking at some iGo screenshots, Avenza probably won’t be a good fit. It doesn’t offer turn by turn directions nor does it automatically center on you. If you drive out of frame you do have to manually move the map.