
Or you could try a booster bath, which is lightweight and can be moved if necessary. I've got a "spaniel" sized one (medium) which I now use in the shower room (it fits nicely in the shower tray) and when bathing bigger dogs I just move it out of the way and use the shower tray for them. I was wary about these baths, thinking they were quite flimsy, but they are in fact quite stable, despite their light weight.
http://www.groomers-online.com/product.php/3338/booster-bath-medium?gclid=COXI2uWqkbwCFYUewwodhGQA9gAt my previous house I had the larger size one which easily accommodated my Goldies. I also had an outside washing station with hot and cold water so could use it outside, and also used it inside in the utility room/conservatory with a shower attachment on the sink taps. The waste hose I just fed out of the door. It sounds a bit ramshackle, but did in fact work well.