Docj, agree all makes sense.
I would put forth that a a situation you observed makes a strong case for a properly placed antenna and 4G amplifier/repeater.
" At the rural location where we have been for the past couple of months, unamplified phones can manage to connect using 4G if they are outside but inside a building the reduced signal strength results in them running on 3G or even 1XrTT"
Strong rationale for a properly placed antenna and 4G amplifier/repeater to give them a shot at 4G inside and the increased data rate inside the building/camper.......