Maybe not something commercial landscapes might do, but,
I wonder if folks there / in similar, extremely marginal areas treated it like something you might cut back to near the ground right before a significant cold spell, then cover w/ heavy leaves ..couple layers of Palmetto fronds perhaps? thru those episodes if that would be enough to get the roots / any section of remaining trunk thru sub - 30F cold spells.
Seems it grows fast enough, especially there, that it would be flowering not too long again after pushing new growth, esp. if sited in an ideal spot.
Yea, it's St Armands and " cold " really isn't an issue there, but, specimen there has been planted since... ..at least.. 2013, perhaps a year or two earlier? ( 1st shot )
..Bad quality street view shot, but still there in '19.
iNat Obvs. from 2020 < Blue >
and again last fall < Purple >
..That's over a decade of surviving a few chilly winter evenings. Not bad, imo..