Shallots - plant now or wait til spring?

Hi team

I have just received a net of shallots, the longer, echalion type, called 'Longor'. Would it be better to plant them now, or wait until spring? Or pot them up now and keep them in the unheated greenhouse over winter, so they root well for spring planting? I had a complete disaster the winter before last because of the heavy rainfall and so I lost them all; once bitten? Any advice gratefully appreciated!