Yes, I do have pots of Nerine sarniensis, Lorrie. These aren't said to be as hardy as N. bowdenii, but have been fine in terracotta pots in my unheated greenhouse. I think they'd be do even better if you can keep your greenhouse slightly warmer as you say.
And E-J, as you don't know what variety of Nerine you have I'd be cautious about planting them out, and would prefer keeping them in a large pot. The bulbs slowly multiply to get ever more congested, but congested bulbs like these appear to flower well.
I'd suggest potting into a loam-based compost with extra grit added, as this will keep the bulbs going for several years.