I think you can ask potential PhD supervisors directly if they would consider a distance learning student, or at least allow you to work mostly from home, as you probably will have to go to the university at some point anyway.
This arrangement was offered to me right off the bat by one professor I spoke to, but that was a computer modelling project which didn't require a lot of time in libraries, archives etc. I don't know if history would be so easy.
Also it sounds like you should do a master's degree first. I would recommend this to anyone prior to looking for a PhD.