That's a lot of volume to try to heat with that amount of power.
If you can't insulate, then you need to stop all air flow. Floors, baseboards, window sills(enclosing woodwork), door sills, and any ceiling woodwork, plus an air tight plastic seal on windows will pay off in the long run.
A couple of IR sensors could determine IR direction thru window, and control a curtain.
If you can not increase electrical power, you might consider a small potbelly stove. There ought to be a chimney nearby in that old house. If not, or unusable, there are small chimney kits now.
You should find coal nearby. Always boil water on the stove.
If you can't insulate, then you need to stop all air flow. Floors, baseboards, window sills(enclosing woodwork), door sills, and any ceiling woodwork, plus an air tight plastic seal on windows will pay off in the long run.
A couple of IR sensors could determine IR direction thru window, and control a curtain.
If you can not increase electrical power, you might consider a small potbelly stove. There ought to be a chimney nearby in that old house. If not, or unusable, there are small chimney kits now.
You should find coal nearby. Always boil water on the stove.