It seems that in the US the charger port will be on the passenger side. Will this be the same with UK RH drive or will it be on the driver side? How is it on the model S?
To us, it's on the driver's side. ;) It will probably remain on the left side of the car for RHD variants.
The charging port will likely be on the side that favors Supercharging, (left/driver's) side in the US.