What is your minimum temperature? Clivia can normally handle down to just under freezing here in south Africa. Damagae occur when we get 'black frost'.
Cyrthantiflora is Noblis x Miniata. Nobilis can take more cold so Cythantiflora should be more hardy. Some of the have beautiful flowers!!
Regards
Dries

It really depends on the year. Being part of a set of narrow islands means we don't have the moderating effect of a big continent. We have 'weather' more than 'climate'.

This year the low temperature was around -3C and it was 'gone by lunchtime'. We also had a series of extremely wet days and bursts of chills from Antarctica.

Microclimates make a huge difference; a friend about 200m down the road has a big clump of C. miniata growing under native trees (evergreen) beside her house and they remain relatively untouched.

I'm looking at my own micro-climate to see what I could do to improve matters.

Thanks for the info on cyrtanthiflora. I'm looking forward to that.

Meantime - I'll continue the long, slow watch for the hardier plants.