An addendum to my previous post...
I've been riding to work all winter with departure temps as low as 18 degrees F.
If you're going without heated gear, I suggest looking into "moose racing" handguards (velcro- fabric covered foam- easy on-off, cheap), snowmobile gloves, a riders comfort st wind plus balaclava, wind proof jacket with liner and a sweater underneath, windproof pants with insulating liner.
truth be told, the handguards made a huge difference in my comfort level and I'm ok at usual city speeds for ~45 minute with this setup. I'm fine on the highway for a 30 minute run as long as the temps are above freezing.
spwg