Hello! For this season why not try some winter flowering heathers, ericaceous compost is good for these. Variagated ivies which would trail over the pots would be fine. Pansies and a selection of winter flowering bulbs interplanted would add colour in the centre. The bulbs could be planted in three layers, daffodils at the bottom, a layer of compost, then some tulips, compost and top off with a layer of crocus for example.This should give you interest over a long period. Primulas too make a colourful display. As the winter progresses you will be able to see how much the plants are subject to wind damage and be able to plan more permanent planting accordingly. Good luck.