Thanks Muddy.
No, I leave them out.
Group them together, loosely tie the leaves together to protect frost getting in the ‘crown’.
Put some bark chippings over exposed soil to help keep the frost out, then wrap the pot in bubble wrap.
It’s a bit of a pain, the winter protection, but I haven’t got a greenhouse to move them into.
If it was really severe prolonged cold, I will drop one of those ‘Bell’ cloches over each plant too.