Winter window boxes

[DoingItForTheKid]

My pelargonium are still doing well in my window box. I can see new buds...will they flower in Home Counties December, or shall I replace with cyclamen?

Perlagoniums aren't very hardy so they'd be unlikely to survive a hard frost. But not all cyclamen are either. Cyclamen Coum would work though. But so would lots of other things - like heathers, skimmia japonica, heucheras, carex, winter pansies and so on.