Im really late to this thread but have been reading it with interest on my phone.
I know it was just conversation but I look at the term off grid differently more similarly to (I think) David's reply. I have an off grid home but to me that means no grid tied power and possibly telco/gas as well and thats about it.
When I think of the individual(s) being spoken about who may practice subsistence living, trying to avoid taxes, bills, overhead, and so on, I think of them in my own term of "under the radar" or "flying below the radar". The term off-grid to me just doesnt cross over but perhaps thats because I live in an off grid home.
All the points have been very interesting and valid. My home is simply a conventional home. No special appliances, no special lighting. Conventional fridge, washer, big screen TV's, on demand water heater (propane), and so on. Of course how conscious and conserving one has to be is dependent on how much you choose to invest in the system but I have had no problems.
That being said, my motivation was a $25K cost from the utility to bring power to the property at which point I would be at the dead end of 8 miles of older line (prior to the 2 miles new) which see's frequent outages, voltage fluctuations, and so on. I simply wasnt interested in that expense and then paying a monthly bill for service.
Something I did find interesting though was how many seemed to have a problem with someone choosing to live a very modest/frugal/humble life in an effort to require very little money to exist. Of course psyche issues aside (hoarding, hermit, reclusive) I just dont see the problem with someone making a conscious decision to live as small a life as possible to perhaps allow them to really do the things they enjoy or are passionate about (windsurfing from a van comes to mind). That taken to a more permanent setup with a house and property but a life lived with a conscious focus on keeping things minimal could allow for a tremendous amount of time and resources for the things that truly make that person happy. I guess I mean it doesnt always equate to some guy muttering around a building with a dirt floor talking to the walls and not bathing.
I think a well planned setup in the right area could allow someone to live a pretty rich life for an amount of money that wouldnt require an IRS filing but I dont have it in me to do it.
With regards to my home much here was spot on, you will never have the power to run major tools without a monumental investment but I have a commercial shop (on the grid which is also very low overhead) and its my work so when I go home I want to be away from all that. I use to always want my home and shop to be together (were for years) but having them separate has been something I really enjoy though I could easily see it from the other side again one day.
We did have an outhouse early on while we were getting setup and I too was one who despised public latrines and porta-john type affairs but to be completely honest I think something is different when its only you. I had no issue with the outhouse whatsoever and actually enjoyed seeing and hearing the wildlife/birds and so on. Agreed winter sucks, and if you were sick it would suck worse (never was thankfully). That said, getting the bathroom in way back then I have said may times I'd sell you the toilet for fifty bucks but you couldnt give me a million dollars for the shower. (well... :-) ) Living without a shower and taking old school bucket baths just plain sucks. I would say a shower and washing machine are the two hardest things to live without.
It of course doesnt pertain to the reclusive/personality issue types but for me its exponentially harder to do as an individual as opposed to two people also. Living a remote/rural life really makes you understand why people had lots of children. Im sure boredom led to frisky behavior, and a lack of contraception, but additionally you are breeding a workforce and a much needed one at that. When I read, watch programs, meet people, who have lived long periods in remote solitary lives Im very humbled. It would be extremely difficult.