A short wheel base Series Land Rover does not have an impressive range. It left Solihull with a 10 imperial gallon (45,5 litre) fuel tank underneath the right front seat, and with a conservative 7km/litre fuel economy it can travel a mere 318.5 kilometres before it needs to visit a petrol station.
That is 500 metres more than the distance from Sassnitz to Berlin:
Auxillary fuel tanks
There are some solutions that can allow you to bring more fuel.
A semi official upgrade is the military auxillary fueltank under the left front seat.
Companies also deliver supplemental fueltanks to be mounted in your rear fenders (30 litres pr side), vertical 45 litre tanks that are mounted in the rear tub behind the front seats.
The genius jerrycan can be mounted everywhere.
There are kits for mounting them on your front or rear fenders (don’t crash), on your roofrack, and slots for jerrycans that you can put in your fenders. These are original modifications for many army models.
You can get a long row of other fuel carrying options, eg the 100+ litre tanks with pumps, that can be used to transport fuel for diggers etc on a building site.