I can't give a definitive answer but this variety (Gilliflower btw) originated in Truro, Cornwall which is the mildest county in the U.K., ie somewhere around z9. Fuchsias are winter hardy there. The average winter temp is around 41f. There is also year round rainfall. Your cold winters and (presumably) hot summers would be far from its native climate.

I suppose there's one way to find out .....

See if your government agricultural service has information about locally suitable apple cultivars.

Cornish gilliflower survives in northern zone 5 in the U.S. A friend who collects antique apple varieties has this one growing in S.E. Wisconsin. He just offered me some wood for grafting this spring if I was interested. We normally get to -15 below zero in winter. This year will be a good test as we got to -22 which is not the normal winter weather pattern.

I have never tasted this variety so I said no to the free scions and chose others he offered me instead (spartan, KIng David, Hooples Antique Gold).

He grafted his original Cornish Gilliflower tree from wood he collected at a nearby orchard that specializes in growing old varieties (Weston's Antique Apple orchard) in a nearby village. He had perry pear varieties as well to offer me.

Floral:

Since I turned down free scions on cornish gilliflower from my friend due to lack of knowledge about the eating aspects of this variety, can you offer any firsthand information?

When does it ripen? For cooking only or is it a decent fresh eating variety? Now that I blew my chance to graft it, I just wonder what opportunity I turned down. Always intrigued about antique apple varieties so wanted to learn more about this english variety if you can enlighten me on this topic since it originated in your country. Thanks!

I know it's an eater but I've never grown it or tasted it. I was only giving background information on the tree's provenance. I wanted to show the marked contrast between its home habitat and a place where - 35 (f or c) can happen.

Google gives you this: https://www.orangepippin.com/varieties/apples/cornish-gilliflower I see that of the registered trees in the UK only two are in the North of England and even there they'd never ever experience temperatures as low as -35 f or c. From the descriptions it sounds like an unattractive looking, temperamental apple but all is forgiven when once tasted.