NO contrary to popular belief going overland is not possible in the UK, apart from maybe “common land” like Dartmoor, Exmoor, maybe the New Forest or the Yorkshire Moors, we have FIELDS here with hedges and fences not open range and fields are not linked together so you cannot drive into one then another then another and so on. there are some “green lanes” and cycle tracks(which could be accessed for vehicles with the use of boltcroppers# cough cough#) but they don’t link up with each other. I live in an area where we have deep, deep lanes which you cannot see over in a normal automobile, deep ditches and granite walls, many larger vehicles-delivery trucks and coaches- become stuck in these lanes by blindly following their “sat nav” instructions. these lanes are mostly one vehicle wide and easily blockable in a SHTF event. these are the routes I use normally avoiding the use of motorways but I use them all the time and I know where I’m going, many locals use them too but strangers would get lost as they are not always signposted.