Well it's certainly not the best time of year for those motivational, spirit lifting rides, so it's inherently harder to be quite so enthusiastic in these months and I do empathise. You'll naturally spend less time out on the bike if it's dark, cold and wet. Your routine does sounds a little, erm, routine though, so if it bores you, don't do it.
I'm not sure what your goal is, is it building cycling fitness? Weight loss?
Try mixing it up, give yourself a highlight long ride to look forward to on a Saturday or Sunday (dependent on weather). Do a good turbo session once in the mid week, and the rest of the time go walking for a few miles twice a week, have a good 40 min swim, anything but cycling. You'll look forward to cycling again when you make it your reward or highlight of the week.