I charge to 90% nightly on a 48A 240V circuit, so my charge is usually complete by 9-10pm. I see reduced regen every morning, but it's a little colder here in NC.
Even if I pre-heat the cabin, I'm still experiencing reduced range and regen from a battery with 10-12 hours of moderate cold soaking. Nothing as bad as sub freezing temps, but low 30s and 40s.
Definitely looking forward to being able to pre-heat the battery on wall power. I won't use it every day, but I will definitely use it for trips where I can skip a supercharger stop that might be 15-20 minutes off my travel route.
Try setting the car to charge later at night... I set mine so that it starts at about 3AM and finishes just before I need to leave for work. This limits the times I see reduced regen. I am in Raleigh so similar temps etc. You can start the charge at night and see how long it is projected to take to determine what time to set the charge timer for.