OK, Up date.
Thursday, I brought the panel in from sitting under a few inches of snow, the voltage was 1.5v and I had the radio powered off. I was little disappointed the voltage was so low with no load, but This is an older panel and it was buried in the snow.
I updated the firmware to the latest release and set router mode. I then placed it outside later that night. I think it was -25c overnight.
Friday was overcast and light flurries, the panel was sitting up a little higher and didn’t get much snow on it. Friday night the temperature continued to drop to -35c.
Saturday was a great day. One upside to extreme cold weather, clear blue skys. The panel was in direct sunlight for most of the day. I had to move the panel from the backyard to the front yard later in the day to keep it from being shaded by my neighbors house. The temperature continued to drop into the night.
Sunday morning when I got up it was -44c, I grabbed some gloves and brought it into my garage to open it up and check the voltage, it was 2.5v and the radio was still powered. So far success. Closed it back up and its still outside.
1 disappointment, and I’m not sure why right now. Since turning on router mode It never shows up in the Metastatic App for a Bluetooth connection. This could just the power saving features of being in router mode. But more importantly, it never appears to be online in the Mesh. When I connect to my T-Beam and send a message, the app only ever shows 1of1 devices. But as far as cold weather charging and keeping it powered throughout the night, I think its doing well.
If anyone is curious what its like to live in an area that gets this cold… this is what happens when your windows don’t seal real well after a few years. All of our windows get condensation on them and they freeze on the inside.