That's a standard IoT usecase almost all telcos offer.

We have industrial SIMs with our own APN and get a IPSec tunnel to the Telco where we have a dedicated network to see our devices.

We have about 20 client devices, I would very much prefer to throw a bunch of APs into the warehouse and it just works - DECT can do it, so wifi should, too. I'd settle for 10mbit/s!