Hi again, Richard - Yup, I revisited Idledale, saw the cabin my Grandfather and Grandmother built and was surprised and somewhat saddened by the changes since my childhood. Some areas, around Bear Creek were totally unrecognizable.
Yes, REAL boondocking can be a disappointment due to unruly neighbors and previous campers. We tend to favor Forest Service and National Park campgrounds that are somewhat "civilized".
The "pulling" weight of your receiver is the 5000#, as I'm sure you know, and if your 15ft HiLo weighs 2600, you're fine there. Your tongue weight is the potential issue though. It should be in the 10-15% range and ideally at 12-13%, or around 310-330# If you DON'T have a WDH, virtually ALL that weight is on your 4 Runner's rear axle. I'd get your setup weighed to find out how much weight that axle is carrying, with you and your camping supplies loaded. The sticker inside the driver's door will tell you what your limits are. My 17ft HiLo has a tongue weight with empty water tanks of about 500#. I HAVE to have the WDH to keep the loading on the rear axle of my F-150 within limits. I suspect you would be better off with a WDH now and if you get a larger trailer, I think you definitely need one.
My 17ft HiLo does NOT have a separate dining and sleeping area, unfortunately. The dinette table lowers into a sleeping platform on the curb side and the couch area opposite on the street side pulls over to form a "king sized" sleeping platform that takes up the entire area. We use sleeping bags so preparing for sleep is fairly easy. And, we sleep "longwise" in the trailer, so don't have to climb over each other if we get up at night. If I'm by myself, I simply use the dinette side only and just leave it down. We virtually always eat outside, under the awning if it's raining.
Hope these thoughts help.
- Jack