It depends upon your age and enthusiasm for getting out there when the clocks have been set back an hour and it's oh-dark-thirty; the weather forecast has a N'oreaster storm with possible snow starting at 2 pm! It's not just about protected bike lanes; it's the weather, the temps, how you are feeling that particular morning and the idea of dealing with traffic in those early morning hours, knowing most people are half awake and very inattentive; just to get to those protected bike lanes.
In my younger days, on my Motobecane Grand Touring, I tried it a few times; albeit alot longer 30 plus miles, one way to get to my military duty station. Knowing I had 2 days of duty tempered the thought of having to repeat that run 8-10 hours later, so that was a comfort. I found in the longer days of sunlight in summer, worked the best. This particular time of the year however, can be potentially dangerous for us.