Just some thoughts on possible causes of your problem.

I would not surprise me if Ford programmed the FEH not to use regen if the battery temp is below a certain temp. Charging is hard on very cold or very hot batteries. It may be to protect the reliability of the HV battery.

What is odd is the ABS warning light. I can't imagine that being a "normal" response to being parked outside in subzero weather. I would ask the dealer about it. Perhaps the brake system could be flushed to make sure there is no water in the brake lines?