You could have
http://www.camping-utahbeach.com/en/, not sure min nights restriction but there are 2 Aires close by, one on the D421 and the other just off it
Utah Beach
Aire Camping-Car Park
OUVERTE. Dans la Manche, à Sainte Marie du Mont, au pied des plages du débarquement, l'aire CAMPING-CAR...
Ouverture : Toute l'année 24h/24
(+33) 0 805 69 48 69
- See more at:
http://www.camping-car-park.com/#sthash.jVfXceLx.dpuf
see also
http://www.camping-car-park.com/node/331
The other Aire is on the D421, c 200 mtrs from the Museum, which is well worth a visit, if interested, at the end of the bus parking.