[lrt's friend]

In the case of Yarmouth NS, it depends on where official temperature readings are taken. Often this is done at an airport and those are often situated inland. On the east coast, there may be significant temperature variation between a coastal location and a short distance inland because of the direction of the prevailing winds.

I do know that Magnolia grandiflora (the evergreen southern Magnolia) is successful in Yarmouth NS so I think if any place in eastern Canada will be successful with the Chinese Fan Palm, this would be it. I would like to see someone there with a sheltered garden close to the coastline try it.

You really have to think whether Sable Island is suitable for growing much of anything as it is likely windswept with salt spray.