The glue pot died 20 minutes into a 40 signature job

So last Tuesday I'm at my bench in the garage working on a big rebind order, 40 signatures, all hand sewn, and my old PVA glue pot just up and quit on me. Not even a sputter, it just stopped heating and the glue went cold and chunky right when I needed it. I had already trimmed and pressed everything, so I'm standing there at 9pm with half the spine glued and the rest just sitting there drying wrong. I tried warming it in a double boiler on the stove, which felt insane, and of course I got it too hot and it went all stringy on me. Lost about 3 signatures worth of paper before I gave up and cleaned off what I could with a warm damp cloth. Now I'm looking at a $60 replacement pot but part of me wonders if I should just switch to cold glue and stop fighting the heat setup. Has anyone had a pot just fail on them mid project, and is there a way to keep the old glue workable while you swap in a new one?