I have a similar problem with the running water being upstairs. I have a 7 gallon plastic container with spigot in the darkroom that I fill and use a holding bath. This is temporary but the darkroom may not have running water until late this year so I deal with it. Works pretty well most of the time, but certainly not as convenient as having a sink in the darkroom (and no sink upstairs large enough to wash prints bigger than 8x10, except the bathtub which is too back breaking. I use successive still water soaks which saves water and gives a good wash but is a PITA.)