I live in Florida, so I'm not really concerned at all about the coolness of the home in the winter. However, I'd obviously like to save as much energy as possible while gone for the day during the Spring/Summer by setting out Nest thermostat to the maximum safe temperature while away at work -- unfortunately, I'm having a hard time finding what this is.
I say safe because Florida is notoriously humid - I want to save money, but not at the expense of harboring mold behind the walls or something.
I think you're asking a question that's analogous to "how do I measure the length of these pieces of wood, which have varying widths and densities, using these kitchen scales". Length and mass are related, but they're not the same thing.
You've asked about managing relative humidity by using measurements of temperature.
Don't. Temperature and relative humidity are related, but they're not the same thing.
Manage relative humidity by using measurements of relative humidity. Use your dehumidifier, heating and cooling, to keep the relative humidity below 70% or so. And when the property is occupied, keep it in the range 45-55%. That will be the most comfortable and healthy range, minimising the hazards from dry irritable air, dust mites, mould, and so on.
If you find particular spots that are susceptible to mould (these will be spots that are colder than the rest of the property), put the relative-humidity sensors there - you need to keep these spots well below 80% relative humidity: 80% is where you start to run the risk of condensation, and thus mould.
