Multiple Thermostat Sensors?

[Kip Cline]

I bought a 4 unit apartment building. 2 units upstairs and 2 down. There is one furnace that heats the whole thing thy the landlord pays for. The thermostat is currently in the basement where the tenants can't mess with it but turns on and off based on the temp in the basement which is much different than the second story making it hard to regulate. Is there a way to add sensors in each unit and still have the control in the basement? What would be the best way to heat this building? I'm curious what kind of modern thermostats there are. Would in need to have internet to operate wifi thermostats? I don't have internet, each tenant pays their own.