No reason to be scared or panic or change your driving routine.Ok well that scares me! Because I cannot take a 3 to 4 hours trip, not with work or on the weekends. It will be hard to drive around for 3 hours also. I don't know where I would go! They told me the battery comes full charged. I was going to ask the dealership while they are doing my oil change to check the Deka and give it some juice of it needs it. But now that you say it will not work to give it 100% with an external charger that is concerning.
A battery at 80% state of charge can still provide plenty of CCA to start your vehicle at -10F. Just drive as you always have the last 10 years. A 100% state of charge is not required to start your car at cold temperature, but it does increase battery life.
How long did your NAPA battery last?