What a bunch of weenies! You do realize that people go downhill skiing in much colder weather than this, and they don't wear heated vests or have heated grips on their ski poles.
Put on some layers under your jacket, wear decent riding pants (I don't even need the liners in mine they are so warm), wear ski gloves (a lot like bike gloves, but not so ridiculously priced), and a balaclava under your helmet and go for it! Just be sure no skin is exposed, and let a little air vent into your helmet so your visor doesn't fog. I commute across the Bay Bridge, and did so this morning, and am never uncomfortably cold.
Now, I have been cold, but that was when I was skiing down the Monte Rosa during a blizzard when it was about 15 deg. F. Then there was also the time I was in upstate NY, it was 6 AM, I needed to report for duty, and was trying for an hour to get my Austin Healey 3000 to start in -25 deg. F weather. THAT was cold. Riding across the Bay Bridge is never cold if you just wear a little extra.