Sesbania grandiflora

I've got one plant from a packet of seed which has been planted in a very sheltered spot and is now about 2 1/2ft high. Could one of our tropical gurus tell me roughly how hardy or otherwise it's likely to be, please? If it won't take frost, would it be feasible to wrap it up completely for the winter or would it need light and air?
The same dilemma applies to the variegated Pandorea jasminoides, although that is growing against a sheltered wall....
All I want for Christmas is a nice, big conservatory

 

A far as I know, @noisette47 Sesbania is not hardy at all, I am not sure of the lowest temperature it can take but I don't think it will survive below 8c. If it did it would certainly defoliate and even wrapping in fleece or covering with a fleece bag it would still get killed off. It needs a sun room/conservatory to overwinter.

 

Ah, thanks for that, Strongylodon. It's had a brief brush with -1C which has indeed knocked a few leaves off, so I'd better dig it up and get it into the house pdq! I suspect it won't like root disturbance either but it definitely won't like January and February outside!

 

I've grown sesbania punicea in a cool greenhouse overwinter, but have a feeling grandiflora is more tender.

 

Like Pete I've grown S.punicea successfully by overwintering in a cool greenhouse and pretty dry (ie - dormant) but the white form of S.grandiflora didn't make it under the same conditions. I will try again (I still have seed) but in a cool room with a bit of humidity.