Submit later option
I recently found myself in a neighbourhood that had a few potential POI submissions such as old churches and parks.
While I was able to have PoGo open and interact with pokemon on the map I was not able to submit a new Pokestop as the local cell reception didn't seem sufficient to upload the 2 photos (approx 24mb in total) and ended up having to abandon the submission as it timed out a couple times.
Seeing as how Pokestop scanning has a submit later option, shouldn't Niantic look into a similar option for new POI? Newer phones take better quality photos that take up more space. I'd much rather send the submission via my WiFi at work or home later.