Jan, don't know if it would apply to your setup, but you might check into one of the 'on demand' hot water heaters. They can provide pretty much unlimited hot water at a constant temp, they are basicly hot water heaters without a tank. Friend of mine has one in his barn and says it works great. Wish I had one for our guest bathroom, like the idea of not heating water all the time, just when you need it. Keep us posted on what you end up doing.