Smart / WiFi Thermostat without WIFI access?

[Margie Kohlhaas]

I have a triplex rental and two of the units have connected utilities. The guy in the middle unit can't figure out how to run his manual Honeywell thermostat. He either leaves it on Heat or Cool but doesn't understand how to change temp. Both of the units pay for their own WI-FI. Is there an easy way, I can install a Nest or something that I can remotely program or access myself to manage their heating/cooling settings without having to tie the system into their WIFI? Tenants typically stay a year or two so I don't want the system tied into their WIFI if I can avoid it.