In 1998 I had to go to England to participate in an academic conference in Cambridge, so I contacted various dialysis units in the area which accepted guest patients. The usual reply I received was "Give us your name and telephone number; we'll put you on a list, and when a place becomes available sometime in the next one to four months we'll call you and tell you when you can come."
Dialysis patients should be able to enjoy a holiday where they want and when they want.