Not sure what is common practice, but my car was charged to ~50% IIRC and got it up to ~80% before heading to a Christmas party (picked it up 1 year ago today). I made it a point to not romp on it until the next day when it was charged to 86% and the family was with me. I won’t forget that moment. Hopefully you can find a clear road with good traction before swapping to winter tires.
Totally depends on the delivery center and their process.
At ours, vehicles are delivered only after a full detailing and with a charge to 100%. Both our 3 & X were delivered just like that - I really appreciated their attention to detail!