I'm considering getting a u810 for extending winter backpacking trips where temps could fall well below 0F. Nonoperating temperature is the only things that actually matters for me, and I see that it only goes down to 5F for the u810. So...what do you think would happen if the tablet saw much lower temperatures? The two parts I think would be at risk are the screen and battery. I'm thinking I could put it in a freezer bag and keep it close to my body, but this may not always be possible since it'll be competing for space with batteries and water pouches. I'd much rather keep it in my pack when I'm hiking.