Also the fad for putting portal axles from a C303 onto a Defender. I'd read the Defender's side slope as 37 degrees, whacking portals on would raise the truck by about 8 inches if you up the tyre size too but because the landy's not designed for it, the CoG would be far higher than the C303. I know the pinz tipover is rated at 43 degrees, but like the landy they don't state what model so the more top-heavy ones, e.g. the Defender CSW and the FFR K-model pinzes are probably what get the rating with the other lower CoG versions getting better. The 6x6 pinzes have an even higher likely real-world rating due to the rear suspension design.
Also none of the tip-over ratings mention loads at all, so they're probably all playing it very safe.
Halfords rubber-band tyres on wide wheels... Or double-up wheels like has been done on a few occasions, there's a pic or two on 't' internet of a series that had doubled wheels, someone on here posted a link to it many years ago, the mod had been done specifically to get it up some boggy mountain or other IIRC. Or it might have been on the "Land rovers across britain" dvd.