Well, today was my very first ride from my house to the office, LOVING IT!!!!!

I had one issue, it is about 27 degrees Fahrenheit and about 2 miles into the ride my iPhone stopped working. I discovered it at about 5 miles and the phone was claiming to be too hot. Through me for a loop for a second until I realized that the error message was wrong and it was simply too cold.

Ok, I know I can put the iPhone in a pocket, but what about the other electronics, like the speed and cadence sensor? I am running with a Wahoo RFLKT+ on the handle bars and in time I want to get a bike GPS. How do I keep these things functioning in sub 30 degree temps?

In the winter, I just went with a basic little bicycle computer. It would work down to about -15 or -20C. Any colder than that and the screen would go black. So if I wanted to know my distance, I mapped it out ahead of time. I also didn't tend to go too terribly far in those temps ... even my centuries were short loops on familiar roads.

For the sake of commuting, back and forth on the same route(s), I map them out on MapMyRide and just log each ride, no need for electronics. For touring, I will want a cyclocomputer but for regular commuting, no.

My backpack has a small pocket where it touches my back.
I put my iphone in that pocket.
A bonus is the backpack keeps my back pretty warm.

I don't have any personal experience with this, but you can try getting a waterproof phone mount. If it's airtight, the heat from phone should keep it warmer than having it out in the cold wind. Sorta like a rain jacket.

Funny, I received the same error message from my Iphone of being too hot! I started carrying mine in my vest pocket under my outer jacket layer. That solved the problem even after 3 hour rides. I also use Map My Ride and don't bother with other electronics with temps below 10 degrees F.

Now the only issue is keeping my Powerbar from breaking my teeth!

On my last ride that was in the 20's I went outside with my phone being around 80% and after an hour I take a look at it and it's dead. I got home and plugged it in to charge and the battery was 50% once it kicked back on. Definitely taking my portable usb charger on longer cold rides.

I'm surprised the iPhone gave out that quickly on such a "warm" day. My only time having it cut out was an 18F ride of about two hours; it shut down a few minutes from home. I've been keeping it in a pocket since. As far as other stuff (I have wahoo bluesc, rflkt+, and stages pm), I haven't had anything else die on me, although that 18F day is the coldest I've yet been out on.

I carry a cell phone inside my pocket for communication or if I have to make an emergency call or something. Other then that I don't use any electronic gimmicks on my handlebars, except for lights.