Hmm, your situation looks like unicorn-hunting with a twist (well, not an actual unicorn, because you said you would be okay with a vee, which is a huge step forward from most people, trust me!).
I'm not very familiar with Intentional Communities, but I think reading about those, maybe joining a few online communities etc. would be worthwile. More than for someone to be poly-friendly, you actually need someone to be country-friendly.
I would also advice you look for friendship first. And more than a holiday off the farm, it might be more useful to bring prospects for a work holiday on the farm (with their full knowledge and consent, of course!). I'm reminded of a reality tv show back here where men and women living on the countryside and working their farms are looking for brides and grooms interested in sharing their life and work.
As per RP's advice, I think it's vital you focus your search on women who have economically viable livelihoods of their own, be they retired or able to work from a distance. Also, are you only looking for ex-pats living in Bulgaria, or are Bulgarian ladies also an option? Brushing up your language skills and contacting the Bulgarian poly scene, if you haven't already, might be a wise move.
Basically, you are looking to win in the lottery, twice, first finding a de facto unicorn and also someone who would be willing to share your life and work and the very special circumstances that come with it. LDR or people interested in intentional communities with no romance might be something you have to consider settling with.
I'm not sure if this was addressed already, but have you thought about extending your search to males and/or other couples?
Me: bi female in my twenties