Hi !
We currently live completely off the grid about an hour outside Las Vegas. Our house has all the regular amenities, even though we have no public utilities. Our electrical needs are provided by a diesel generator hooked up to a bank of 32 batteries and inverter; it runs once a day. (We have friends that have their place running almost exclusively off solar with the same set-up.) Our well pump is solar, and the water heater, stove are propane. We use direct TV as I'm sure many here do, and our internet service is a satellite connection through Wild Blue - we tried using a wireless modem, but our cell service is terribly unreliable up here and it was a real joke to try and get any kind of decent connection.
We were leery of what living off the grid would mean, but after a year up here, we love it!

The place you are looking at sounds great - we would actually love to have our same type situation someplace with real trees! We have found that we are much more responsible with our power now that we generate our own, nothing is allowed to seep energy! All electronics are on power strips so that when they are not in use they are completely turned off (you'd be surprised at how much power you save yearly by not letting appliances slowly suck away electricity.)
I think your idea of having people stay there is plausible as well. My best friend Brynne, paid for a 6 week herbal apprenticeship at a Maine farm, which she really enjoyed, and it's apparently very popular.
At any rate, good luck with things - I sure hope it all works out for you!
Oh, here's a pic of our "off the grid" house....