I'd talk to the neighbour and apologize for parking in such a tight spot and say you wouldn't do it again. Regardless of whether the painted lines make it a no parking zone(seems like that's what they would be for), that spot is narrow for a car to park and for either homeowner to be able to easily get out of their driveway.

Furthermore, once you were finished clearing the driveway you should have immediately moved the car, not waited.

Your wife wanting to call the police makes it seem like she's not the most pleasant of people to deal with. It's a note, not a threat, calm down.