Not yet.. but my prices are going up January to all new customers, so they will find their "regular" price going up if they want back next year.
I took on one this summer, who then said come the winter I wont be needing it, so i dropped them after their second clean.
I dont mind them reducing it to 8 weekly for instance, as the nights draw in and the mornings are darker its easier to fit them in.. Thats why you should save during the summer months on all extra services, to provide during the winter.