The trick with the steering lock is to always park with the wheels dead ahead. Takes a while to get into the habit but the pawl doesn't drop into the lock until the wheel moves off centre, so that prevents the side load on the pawl forcing the motor to draw excess current and trip the fault. It's a pretty poor bit of engineering by all accounts thrown in as an afterthought for the European market.
Low 12v battery voltage is a known creator of havoc. Some replace the 12v battery as a preventative measure every 2 years. The problem is that 12v batteries were developed to meet starting needs of ICE vehicles and the power demand profile on an EV is quite different. I imagine the recent cold snap also played a part in bringing things to head.
Finally, since the low 12v seems to be the root cause from your description of events, it is I'm afraid entirely possible that you have suffered the same as
@HandyAndy and been unlucky enough to damage the HV contactors. During power up the car does a number of safety checks on these and if they don't pass, it don't go. The cascade of clicks you hear when standing outside the car as it powers up is the various relays and contactors being exercised and completing the safe connection of the HV. Just a guess you understand - but if the fault remains after you've changed the 12v battery, you'll need the service centre to diagnose.