If you want to keep the wife comfortable, install a regular toilet. Tote water in to fill the tank for flushing. Run it to a septic or holding tank. Nothing will keep the wife away from camp more than having to use an outhouse.
Let me amend that a bit. Nothing will keep the wife away from camp more than having to use an ill-kept outhouse.
We have indoor plumbing at "Der Barnhof" , flush toilet included. However, for the campground on the back of the property, I built an outhouse. All the women that come by love it. The trick was that I used a lot of bright white enamel on the inside, used a standard toilet seat, and built the thing so the vapors vent to the outside rather than collect on the inside.
It sits over a simple pit only a few feet deep. It is a very low-use facility. If it were our main depository, I would have built it on the side of the hill, had everything fall into a concrete basin and had everything wash into some corregated drain pipe down the hill.
BTW: That's what we do with the house's effluent. The original sewer pipe ended about 10 yards out from the back of the house. I ran 100' of corregated drain pipe down the hill to extend it. Once every season, I move the end of the "poop pipe" a few feet to one side or the other and this keeps things from building up.
That brings up another item: Water.
We were lucky that we had some well made cisterns on the property, one was close by the house. I had the option of hooking up to city water, but chose not to. Rainwater off the roof keeps the cistern filled. I ran gutters to a home made roof washer and then to the cistern. Out of the cistern, I use a shallow well pump and a pressure tank. However, you can get a decent flow from a 12V pump, especially if you use it to fill a tank in the rafters during off-peak hours.