I would suggest that the issue lies around the licensing of the airport and the requirements for night flight, IFR flights, 5,700kg+ requiring certain splay angles and obstacle clearances.
I would attempt consultation and raise the possibility of a NOTAM for the period which would rule out a GPS approach and NVFR ops and allow for day VFR only.
The HEMS units would be affected, but no worse than closing it off completely.