In message , Charlie
Pridham writes
Its almost certain you will have T. urvilleana. The main problem with
overwintering in the house is its size when brought in! since there is
no point cutting it back until flowering is over. I expect that it had
been kept originally in a heated greenhouse, hence its confusion as to
what season it was. Other people (not me) can grow it outside down
here. it will go down to 0 but any lower and you normally lose it, or
it takes so long to recover it fails to flower the following year. Once
you have some cuttings, why not try a bubble wrap shelter outside
against a warm wall, so you can cover for cold nights and enjoy the flowers.

Thanks, Charlie. I think I'm willing to sacrifice a good bit of living
space for the beauty of it!

Then presumably I can try to root the cuttings in spring when it needs
to be pruned, and follow your plan! I think I can find a warm corner
even in this cold part of Sussex...

--
Klara, Gatwick basin