See one of my old posts about a solution, link below
Build your own outdoor power cable
Note the transformer needs to be inside but you can make any custom length of cable to get it to camera outside
You can also buy a higher amperage power adapter and wire several cameras off cable run, make sure your larger amperage power supply has at least 0.8 Amps per camera available. (ie. 5 cameras = 12 volt 4 amp supply)