You have a delightful motel, and we enjoyed our visit. There is one thing I would suggest you consider. I have a plug in vehicle and when I travel I try to stay where it can be charged overnight. If you check with your neighbors you will find that several of the inns in the area have charging stations. I was fortunate to find that the Kennebunk Chamber has a charging stations so I was able to recharge my car during our visit there.
I think you can have a unit put in for not much money. There is a company called ChargePoint to has units located in your area (I used one in a public parking lot in Durham NH). They charge for the use and I would guess they make a profit. They might install one for you both in Kittery and in Sandwich. I’m sure there are other companies to choose from.
We are about to see an explosion of electric vehicles, so over time this type of amenity will become critical.
See original suggestion regarding car chargers.