You have heard of the proverbial sledge hammer to crack a nut, well this
suggestion is like using a JCB to crack the same nut, and for what
purpose. To exchange a few details like a callsign and report amongst a
handful of radio hams on LF. If we were discussing transportation of
large volumes of radio traffic around the world then the suggestion
might have some merit.
All that is needed is some expertise as a radio operator using hand
sent/received CW or computer aided like very slow CW already in use by
some.
One other simple approach might be a crude but effective method of
spaced diversity like using say 3 antennas, one vertical, one horizontal
and one loop and combine the inputs. Which ever antenna is producing the
max signal at that instant would produce the best output to the
receiver.
This method has been used on HF for years and is old hat but very
effective, combining
a horizontal antenna and a vertical antenna. Not a lot of space is
required even on LF if  loaded
antennas are used, of course the more space the better.
G3KEV