At first I misread Fate/Ellipses as Fate/Eclipse, which I thought sounded awesome. So I guess that's my vote.
This may be too much information, but I think all that is required for a holy grail war is a prepped leyline. Fuyuki has been used again and again because there has always been remnants of the grail after every war, since the war fails every time (I think). The leftovers mean that you don't have to wait as long to restart the ritual because the energy wasn't fully used. Think of the grail as a house that keeps getting knocked down by a storm, but part of the house survives so you only have to put up a wall or two to restore it. A lot faster then starting from scratch. So if a group of Magi wanted to build another ritual in say New York or Istanbul, then they can, provided there was a leyline. I say keep Fuyuki or just make up another fake city. Call it alternate time line or universe so we can get away from Heaven's Feel, unless that is our goal, which I vote against.