Land Rover defenders can sometimes be unreliable, primarily due to inconsistencies at point of manufacture, but I found the more recent models better in this respect, but one shouldn't underestimate the capabilities of these utility vehicles, considering 85% of all defender type vehicles are still running since 1948,
I certainly don't think that can be said of most other manufactures that I can think of?
Including Volkswagen! even though there's many still running, from the 60s and 70s, primarily Beatles, and a few split screens, mainly due to their simplicity and availability of parts, same as defenders.
As for getting stuck on wet grass, I can tell you from personal experience, at times it can be treacherous even though it looks rather innocent, but extremely slippery, especially if any slopes are encountered,
doubly so if the vehicle concerned happens to be rather heavy, which I feel the Cali certainly is, so I would have thought it's rather prudent to consider the 4 motion version, rather high on the list of priorities, especially since as far as I'm aware no other off the shelf camper has a four-wheel-drive capability, apart from the occasional converted vehicles,
So I suggest if anyone feels that they may venture off the beaten track or are likely to encounter wet grass I feel the '4 motion California' makes quite a lot of sense, and a certain amount of 'peace of mind, Especially in winter conditions or for towing; distributing the torque between all four wheels, especially if there's any chance of wheel spinning due to slippery surfaces like wet roads, after all it's only the cost of posh radio, which can lose its novelty value rather quickly, compared to the usefulness four-wheel-drive can realise, especially since the fuel consumption is of negligible difference compared to 2 wheel drive.