How to Improve Wi-Fi Only Location with External Device?

We have an app that we use for data collection that ONLY uses the internal location services of the iPad. It will not use external GPS units attached to the device. Unfortunately, we were given Wi-Fi only iPads and I am aware now that this doesn't have a GPS chip in it and half of our workforce is located in Iowa and the areas where they have to collect data are deadzones for cellular and Wi-Fi.

So I've attempted to use the Garmin GLO 2 GPS, but obviously that doesn't work. Is there any device or service that would boost the internal Location Services of the Wi-Fi only iPads? I'm pulling my hair out trying to find a solution. TIA for your help.