ensete (banana plant)

Jilted

I bought a lovely purple Ensete in the autumn, kept it in the house, growing well but noticed today it was completely covered in whitefly - it's about 1m high.  I have sprayed it with light soapy water and put it outside in a very sheltered spot.  I live on the coast of Co. Down on a very exposed site that gets strong winds.  Should I cut all the leaves off and store in our shed?  I thought the whitefly might multiply in the warmth of the shed?  Your comments would be welcome.