The French association AFCE (Association Froid Climatisation Environnement), with the help of UNICLIMA and ADEME has published its study on alternatives for high-GWP refrigerants.
Replacement options are analysed by application sector and in many of these replacement refrigerants are known or even established.
With regards to heat pumps, the document states: Heat pumps in residential buildings are either air-to-air reverse air-conditioning systems, and options are identical to those described above, or air-to-water systems, the most common in France; the refrigerant is
essentially R-410A and candidate refrigerants are the same: HFC-32 and HFC/HFO blends based on HFC-32. For heat pumps in industry, depending on the temperature levels, candidate refrigerants for the future are R-1234ze and R-1233zd
You can find the complete study, as well as the annexes and fact sheets in English here.