And I was pretty happy moving into a house vs. an apartment where the heat temperature was not controlled by me!

In the summer, the temperature rarely gets into the high nineties and almost never goes above 100 degrees.

When I do go outside, it is beautiful and like many others have noted we have so many different temperatures and different activities.

It's very expensive, has horrible traffic on restrictive roads due to the geography, but is very beautiful, not much snow, milder temperature swings, great hiking and outdoor activities such as 4x4 or hot air balloon tours - very touristy.  

I read we could add TRVs (Thermostatic Radiator Values) to each radiator so the tenants can control the temperature and we could track how much hot water is flowing through the radiator.

They canvased the whole city taking temperatures.

Before you move the thermostat you could go a slightly less expensive route of a smart thermostat which would allow you to "monitor" the temperature remotely. 

So do you control the temperature in your tenant’s apartment?

No clue but i would like to live somewhere with an avg yearly summer temperature of 80 degrees, a beach, mountains and good food

Pretty cold down here in Orlando/Four Corners area - well, not the temperature, but certainly the booking rates!