I have no experience with either, so I'm not going to recommend anything.
The MOSFET would cut the current to next to nothing, but it would need to completely restart when you turned the power back on ... don't know how long that takes or whether it would be a problem for you.
Here is an example from TI for one of their other CC2xxx wireless chips which uses power gating. Dunno why they used that fancy switch to do the gating, probably because they don't make discrete MOSFETs
(You should probably use a P-MOSFET by the way, don't think it would be a good idea to not give the HM10 a low inductance ground connection.)