I don't know what kind of heater this is but electric heat is expensive in our area and poorly functioning units can sometimes draw more energy, if the thermostat on a unit doesn't work or the heater doesn't sense temperature correctly you can have a situation where it is always on drawing electric. 

I'm about to start on a similar project, between the snow and the temperatures, the house challange seems easy.

A simple, low cost method...especially if it is only a problem for a few months out of the year...is window units (for heat or a/c) or baseboard heating, to help supplement the temperature provided by the HVAC.

Like a welder that got a welding certificate while in.

Use wire nuts inside the junction box to join the new and old cables.You should also buy a new temperature and pressure relief valve (safety valve) for each new heater, if it doesn't come with one in the box. 

Would you rather be home based in the Bay Area with tons of things to do nearby, good weather, lots of nature, etc. or someplace with little culture, extreme temperatures, bland immediate environment, etc., etc.

I am looking for a thermostat that I can install where I can set the upper and lower limits of the temperature - perhaps by a passcode. 

its hot always.. temperature and just business attitude.

They are similar to heat pumps in that they become less efficient at cold temperatures.

If you’re looking at rental properties, get to know the area and take the temperature of the overall market.