Hi, not sure how good it would be as its open 24 hours but the nearest supermarket for the ferries is the Asda at Newstead Road
which is opposite the Fire Station and only 2 minute drive from the ferry.
(alternatively there is a car park we usually use at Newtons road where coaches and cars park during the day... not sure about overnights though)
Otherwise can recommend a few campsites within a 10 minute drive)
