wrote in message

How can I get heat in this room without going broke?

Electric is the most expensive heat available in New England.

I am thinking
single baseboard heater with it's ownn thermostat - does something like
that exist? Can it be plugged into a wall outlet or does it need to be
hard wired into the main box?

Both types are available. If it is a plug in, be sure the wiring is
sufficient to handl the load.