We have cellular in the bus. He wants syncing to occur when they are connected to Wifi which I have to figure out
Is cellular for the guests use via wifi?
Yes. Quoted comment was in relation to the bus being parked when not in use. Once it connects to the HQ wireless network it can sync. This would actually be a great ansible project I'd think
Wow - the cellular bill must be huge..
In such case you just buy unlimited data plan, making sure there's no bullshit fine print saying unlimited for first 2 or 3GB then fallback to 2G or similar crap.
Who offers these plans?
Everyone offers unlimited plans. The problem is with slowing down after certain data threshold, for that you need to talk to sales directly and negotiate contracts. We did that with RingCentral, where I literally crossed out most fine print on contract and asked for new one with my corrections. I don't know how much luck would you have with wireless carriers.