You added about the right amount of water, you just didn't let it boil long enough. Fermentation temperature control is critical. You could have the best technical brewing day, and pitching the yeast too hot, and/or fermentation temp too high, your beer quality will suffer. You said you could use the spare bathroom tub for a couple of days, that may be all you need. Do you have a way to stockpile some ice or blue ice? Run the water into the tub as cool as is possible, after placing bucket in tub, and if the water temperature is 70* the beer is 5* hotter usually. 75* is too hot for good beer. Cooler is better, and it is only critical for the first two, maybe three days. At that point, room temperature will be okay.