I grew 'Lucifer' when I gardened in zone 5 with no extra winter protection. I've not grown 'George Davidson' but do grow "Prince of Orange' and 'Orange Pekoe' in my current zone 6, again with no extra protection. The latter though does grow in a protected spot on a south facing wall.

Lucifer is hardy.

It survived -30F in a neighbor's garden before I got a piece of it.

Lucifer has spread readily in my 5b garden for many years: no issues overwintering.

My crososmia winters ok in zone 6 with no protection. This year i planted 20 bulbs, they are up in various sizes but no blooms yet.

If you plant them from bulbs, they don’t bloom the first year because they don’t really like the treatment methods that bulb farmers do to them after harvesting the bulbs

"they don’t bloom the first year because they don’t really like the treatment methods that bulb farmers do to them after harvesting the bulbs "

Actually, it is only in colder climates that crocosmia is reluctant to bloom its first year. Got nothing to do with the treatment of the corms.

And while most sources state a zone 6 hardiness, they are reputed to winter over well in colder zones as long as winter soil drainage is good.