Hi there,
Yes in zone 8 Magellanica Alba should survive your winter -Kath :)

I agree with Kath. F.m alba is hardy here near Edinburgh at 300 metres above sea level where it survives frost and snow. If you have not already planted your fuchsias in your garden I would delay until next spring and overwinter the plants in a frost free environment. If they are already planted I would suggest a protective mulch in autumn to help them survive the winter.
Ron