farmers ... friend or foe.

[Tartar Horde]

It depends like so much on the situation, if we are talking industrial collapse etc then the farmers will still be around, and no doubt defend their property robustly.
If on the other hand we see large population die off due to pathogens then there could be a lot of farm property vacant.
The farmers I know all have adjacent farms and keep in contact through radio, and I don't doubt other farmers do the same thing, they tend to be a well organised bunch.
I don't fancy many townies chances taking on a farmstead to be honest, but in the real world it only takes one well aimed petrol bomb