I just want to say that these opportunities exist!
Years ago, I went to the county government and found out who owned the vacant lot behind my house. When I talked to the owner, he was pleased to allow me to use that ground for a vegetable garden. I "paid" him by harvesting fruit off the apricot tree that grew there, making jam and sending him 2 half-pint jars each year. This went on for about 4 years.
When I moved to my present home - I lost that garden and went looking for another. I told everyone what I was hoping to find. One friend said that she knew a gardener and would ask him if he had spare land. He owned rental property which amounted to 1 house and 1 garage on 3 lots. I got 1/2 of a lot the first year but soon had 1 1/2 lots.
I told him that I was like the camel that was invited to put his nose inside the tent on a cold night

. His son now lives in the home and uses 1/2 lot for growing. After nearly 15 years with me being there, the old fellow has completely retired and wants me to take over what his son has . . . I've got my eye on the garage

.
Another friend told me about someone he knew with land and available water. This was nearly the size of the property listed on Craiglist. Except, it wasn't "accessed easily by vehicles." In fact, I had to walk and run my wheelbarrow about 1/4 mile but the setting was absolutely fabulous. I loved it there!!
Things changed in that fellow's life and he sold his home and land. I'd already moved across the road . .

. .
Just driving by, I noticed this freshly-plowed, odd-shaped piece of ground. I stopped by to ask if the owner wanted to allow me to garden there. He said, "No, but I can share my garden with you."
Turned out he raised 5 kids and was left with an "empty nest" and a huge garden space. These folks are always traveling and visiting their kids and grandkids. For 2 years, I didn't even SEE them!
I send them emails and photo's of their property, when they are away. If they have someone living in their home, I try to develop a good relationship with them and help them grow some things in their own garden.
The water has been free. This is in an irrigation district and water is paid on the basis of land-ownership whether the water is used, or not. It is essentially a tax. The property owner has a good number of acres and has most of it in alfalfa, for hay. We have never used more water than allocated for the land.
If you want to garden, don't mind commuting, and are determined to "keep the weeds down" within your borders, so as to make most property owners happy -- there are probably opportunities for the asking. Just, share what you grow.
Steve