Occupant profile: two older ladies on SS, one with mental disability and another with cancer undergoing radiation treatment.

(I never have before, but I can see it would be nice not to have to fish wires for the new owner.)Also, this house is huge and has (intact) radiators throughout.

I thought that C Class meant that the plastic radiator in your wife's BMW cracks and she feels safe waiting for AAA to come and flat bed the car...Westwood?

The most important question, what kind of radiators? 

If the heat is radiators from a boiler, you have to separate the supply piping and return piping for each unit, then you need the extra boilers as well; you might be able to re-gun the oil boiler with something like a Midco Economite to save some money on a boiler, assuming existing boiler is in good condition and not too oversized for the biggest rental unit.One thing to point out is that you will now have multiple burners.

Just as a side note, the stovetop pizza makers use baking stones on the interior to hold heat better and radiate it back out to the food. 

And of course, up there in Vermont, wouldn't you like to know if the bathrooms have their own radiator or heating duct?

If there is a boiler system, make sure you inspect inside of each radiator to check for corrosion around the valves.

Radiator heat piping? 

Is the duplex heated by hot-water radiators?