You don't produce much in the winter anyway, you can brush it off the panels with an extendable broom but it will naturally melt and slide off. Unless you have snow cover all winter you'd likely spend more on the extendable broom than you'd produce from the panels.
My brother-in-law's panels produce just as much electricity at noon in the winter time as they do in the summer time. Winter sun in the Canadian prairies is quite intense, and the panels are more efficient at -20C than they are at +20C.