Decreasing mileage

Fall has arrived in Calgary, and running in the morning is not as comfortable as it used to be. Since the mornings are well below freezing, and the evenings are getting darker, the best time to run is first thing after I arrive home after work. The problem is that going out for a run is the last thing that I want to do at that time. My after-work frame of mind is focused on rest and dinner. So I have not been going out as often, and only manage around 30 or 40km per week.

How can I turn this around and get back up to the 50km per week that I promised myself? I don't think my reluctance to run is purely psychological. Before dinner I really am short on energy. As a trial solution, I am going to bring extra snack food to work so that the afternoon hunger pangs don't hit me as hard.