For an offroad RV I'll take 4WD over 2WD in a heartbeat.
Whether I get stuck "further out or not" with 4WD over 2WD I'd like to leave up to my judgement. Having 4WD is priceless when you wish you had it.
At the very least 4WD allows you to: 1) Get home if you should happen to break a rear axle, 2) get home if you should happen to break a rear driveshaft or one of it's universal joints, 3) get some traction in a situation where your rear wheels are off the shoulder in sand but your front tires (or at least one of them) are/is on the hard surfaced road, 4) and have a low range available for steep road situations in which otherwise only 2WD would be required traction-wise. Of course in having 4WD it goes without saying that both differentials should be manual or automatic locking so that at least any one corner of the vehicle has a chance at traction.
Our pickup truck having 4WD has made it much more pleasant several times in the years that we have had it. In our pickup we even use low range sometimes but leave it in 2WD.
