Heheh, I had a feeling you'd chime in.
It wasn't some poncy grassy field like you'd see in Top Gear or 5th Gear qualifying as 'off-road'. The picture you see is an access road to a forestry service trail. We couldn't get too far into the bush because of the snow; they weren't actively logging, so it hadn't been plowed. We were dealing mainly with ruts about 2-3 feet deep, mud about 2 feet deep, and generally messy stuff that anything without AWD would get stuck. Temperatures were hovering just above freezing, so the ground was thawing and was pretty slick, but still with lots of loose-packed snow. I hope to have some video of some of the gnarly bits soon. The dirt in the area is all a very fine silt, as we were in the bottom of a canyon...the stuff had dried on by the end of the day, and proved a real whore to get off.
Regardless, it was more 'off-road' than I'd venture to guess than the vast majority of X5's around here would go. And keep in mind; its nearly 6-figures of BMW that we didn't want to (completely) destroy. The exhaust was...a little misshapen when we got back.
A three foot deep rut is serious, that's about up to my waist and if one doesn't attack it just right you can expect it to eat your front end. Thick mud at two feet will bog down all but the most capable and well equipped offroaders.
I look forward to those videos, especially bashing BMW's finely tuned exhaust into rocks. No doubt you did much more than most X5s ever will, but that's not saying much since the most offroading those see is being parked on a cricket lawn for a party.