The thermostat issue is worth fixing right away.

Adjust the thermostats? 

The heat would rise and shut off the upstairs thermostat, causing the upstairs bedrooms to get cold.The downstairs unit was a small one-bedroom, and the fireplace would heat the living room to the point where it was concerning from a temperature and CO2 perspective. 

A heating thermostat has a differential; the temperature difference between beginning and end of cycle.

I have been hearing a lot about smart thermostats particularly the ecobee premium smart thermostat and the Honeywell smart thermostat. 

@Bobby Eastman  the other way to save is we do use landlordstat with upper limits on the thermostat.

Reactive Problem-SolvingOperators know problems are inevitable — so they design response systems in advance.Maintenance Matrix: Document common issues (WiFi reset, HVAC troubleshooting, breaker panel locations) with photo guides stored in a digital binder accessible to staff/guests.On-Call Vendors: Build a bench of reliable local contractors (plumber, electrician, cleaner, handyman) with pre-negotiated response times.Tech Monitoring: Use smart sensors for noise, water leaks, and thermostats to prevent issues before they spiral.Communication SOPs: Response time targets (under 5 minutes for urgent issues, under 30 minutes for minor concerns).System: Crisis Playbook Binder — a digital + physical binder with scripts, vendor contacts, and SOPs for every common guest problem.6.

The peak of this movie is billions for programmers and $120K+ Bitcoin. 

Hey @Jules Aton, is it a basic Honeywell or is it a smart thermostat?

I will likely get a smart thermostat (ecobee is what I'm leaning towards) and after insulating the attic I'll just make do with blackout curtains.Thanks again to everyone who provided input!