mini split question! please review..

Hey, ok so I have read and read and read on this forum, many others and many manufactures but my question still has not been answered!!
I want to install a mini split system to heat and cool but I live up north and winter temps average at -22C. Will the compressor still work with a heat pump to heat my grow room ??? I have faith that they will cool them and dehumidify and I like the idea of the HFC but will it work for winter???? Temps do drop to -40 sometimes but unlikely.. They have ones with back up electric heat. Will that help keep the compressor in workign order so the heat pump works? Any info is very useful and im thankful.

The lower temps could cause your heat pump to not work if it isn't charged correctly,-20c may be too cold all together.. If I were u I'd use a hydronic heating system, perhaps an extra zone hooked up to a few baseboard loops (if u have a baseboard system) just because there is no forced air , no filter or whatever. I could see using a split for ac in the summer but wouldn't rely on the heat pump in the winter , although running it as much as possible may save money