Landrover should tow it no bother as long as field is dry enough. Make sure adequate ropes or chains or strops are used. Does the shelter have strong points to tow from ?
Select 1st low and put the diff lock in if it's a model that has it.
As mentioned above getting it moving from its start position will be the hardest bit, if the landy won't set off then lift the shelter a bit as said to unstick it. This could be as simple as sticking a crow bar under each corner and levering it up to release it, perhaps throw a lump of wood or whatever under to keep it up slightly then move to the next corner.
If needed when moving to new location do long gentle curves rather than sharp turns.
Good luck and Let's us know how it goes !
Search youtube landrover towing truck if you are worried about what landrovers can tow...I tried to put a ling but it wouldn't work.