I don't do off-road myself. If I did (and I keep having a hankering to do a bit of exploring), I'd be looking at Fat bikes, rather than the sporty stuff. Most of the sporty MTB's are aimed at going fast off-road. If you want to get into wilderness, you need to be able to cross any terrain. That's what fat-tyred bikes were designed to do.
Rather than have fancy suspension, they have big, fat tyres. Minimal impact on the terrain, and they can cross soft ground where lots of other bikes can't. The original was the Surly Pugsley (I have a friend who owns one of those), but they have become more popular and there are cheaper models. There are places that hire them out so you can try before buying.