People like farms, people like tiny tiny houses. Seems an obvious match. I’very heard from local farmers that, by adding the vacation component to their farms, they have realized more profit from tourism than selling vegetables.
The people we met at market valued the connection they had to our farm through meeting us and eating the food we’d grown. I’ve long felt that if you managed your activities so that something was happening every week (canning, jam-making, cheese-making, sausage-making, wine-making) you could then send a parcel with something the visitor had participated in to them just before Christmas/solstice/Kwanza/insert midwinter festival here. This would not only remind them of what a good time they had experienced, but they would be more likely to return. They would also be more likely to be great brand ambassadors, but also, in this age of crowd funding, potential sources of capital. If, say, you are trying to go off-grid, your regulars could serve to help fund the process, labour to help install/build the infrastructure, and as evangelists for the possibilities.
The rental units could also be used (properly winterized, of course) for artists retreats (and an artist-in-residence programme) and cross country ski vacations. I’ve also seen video of a farm in the UK that hosts a TED talk equivalent weekend, focusing on environmental topics. 300 people, mid three figures per, and the local village gets a major boost as well. The potential for doing reasonably well while doing good is quite high.